The Catgut Acoustical Society Newsletter

Home , Baritone violin, Simone Fernando Sacconi, Vertical viola

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THE CATGUT ACOUSTICAL SOCIETY NEWSLETTER

Number 20, published semiannually November 1,1973

MUSIC COMPOS__D FOR INSTRUMENTS THE FAMILY OF NEW VIOLINS Voorhees Chapel , Douglass College _ _ _ ,__, Octol)er. . lk 1973 k m New Brunsvick/N. J. Sunday ' > ~ P ' *

The four cccpositions on this program are prize-winning entries in a competition sponsored by The New Jersey State on the Arts, Douglass College, and The Catgut Acoustical Society, Inc. The following artists are participating in the performance of these compositions:

Douglass College: Joseph Kovacs, Mezzo Violin Pobert Martin, Tenor Violin Arnold Kvam, Baritone Violin Tale Obiversity of Music: Broadus Soprano Violin Syoko Aki Erie, Mezzo Violin Harold Ccletta, Viola Aldo Parisot, Tenor Violin Conservatory of Musis: William Berman, Alto Violin Montclair College: Bonald Naspo, Violin

1. String Quartet Marino A. Maagini (Soprano, Mezzo, Alto, Tenor Violins) la Two Movements 2. " .String Quartet : . Chang (Mezzo, Baritone Violins) I Outspoken II Exaltation III111 Elegy IV - Tribute V - Last i.ord 3 . "Images" William Duckworth (Soprano, Mezzo, Tenor Violins) In Three Movements h. String Qiartet for New Violins Delia Peruti (Mezzo, Alto, Baritone, Violins) In Five Movements

J. Dramatic Suite for New Violins (1965) Fran's Levin (Mezzo, Tenor, Baritone, Bass, Violins) I Prelude and Chorale II - Toccata and Passacoglia 111 - Air IV - Fugato and Epilogue

At the above performance, an audience of about 65 heard the winning compositions in th« oontest announced in the last Newsletter as well as the Dramatio Suite for New Violins by Prank Lewin. (The Mangini and Duckworth—compositions were played from tapes previously made by the Yale musicians). Composers Peruti and Chang were in the audience, the latter traveling all the way from Arizona for the occasion 1 Our special thanks to the musicians who made this possible. After the performance, the annual general meeting of the Society was held, with about fifty members in attendance. At the Board of Trustees meeting which the primary item of business was the election of trustees. New members of the Board are: A.H.Benade, A.S.Hegeman, D.McGilvfay, and R.E.Menzel. Reelected are: M.A.Hutchins, and J.C.Schelleng. Together witn incumbents F.B.Clough, W. J.V.Doraaleski, R.E.Pryxell and P.Lewin, these constitute our Board of Trustees which was increased to a total of 12 in 1972. Regretfully, and after considerable thought, the Board voted to increase the annual membership dues to beginning January 1,1974. Not only are printing costs continually increasing but also mailing costs which are scheduled to go up again in January 1974. We again urge those of our members wno have not paid their 1973 dues ($5.00) to do so promptly. On September 2, our "Secretary was forced to send out second notices to 149 members nearly a third of bur membership. Our treasury does still have a balance, but far from—sufficient to cover the expenses of this Newsletter and other commitments during the winter. To cover increased costs, we also are forced to raise our charge for back issues of the Newsletter to per issue. COPYRIGHT Catgut Acoustical Society,lnc. 1973

CONCERTOF OF

first Council

School Erie,

Obsrlin State Contrabass

"Statements for G. Gordon Alto, Tenor,

Alto,

Carl Contrabass

Alto, Snail Contrabass

followed, R.H.Scanlon, Creel,

$8.00

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THE CATGUT ACOUSTICAL SOCIETY NEWSLETTER

Number 20, published semiannually November 1,1973

MUSIC COMPOSED FOR INSTRUMENTS THE FAMILY OF NEW VIOLINS

Chapel, Douglass College _ »_. „„_, Voorhees ,_ .1 k1. New N. J. Sunda^ October lk> 1973 " p 'm -

1. String Quartet Marino A. Mangini (Soprano, Mezzo, Alto, Tenor Violins) In Two Movements 2. " .String Quartet : . Chang (Mezzo, Baritone Violins) I Outspoken II Exaltation 111111 Elegy IV - Tribute V - Lost i.ord 3 . "Images" William Duckworth (Soprano, Mezzo, Tenor Violins) In Three Movements h. String Qiartet for New Violins Delia Peruti (Mezzo, Alto, Baritone, Violins) In Five Movements

J. Dramatic Suite for New Violins (1965) Fran's Lewin (Mezzo, Tenor, Baritone, Bass, Violins) I Prelude and Chorale II - Toccata and Tassacaglia 111 - Air IV - Fugato and Epilogue

At the above performance, an audience of about 65 heard the winning compositions in the oontest announced in the last Newsletter as well as the Dramatic Suite for New Violins* by Frank Lewin. (The Mangini and Duckworth—compositions were played from tapes previously made by the Yale musicians). Composers Peruti and Chang were in the audience, the latter traveling all the way from Arizona for the occasion 1 Our special thanks to the musicians who made this possible. After the performance, the annual general meeting of the Society was held, with about fifty members in attendance. At the Board of Trustees meeting which the primary item of business was the election of trustees. New members of the Board are: A.H.Benade, A.S.Hegeman, D.McGilvfay, and E.E.Menzel. Reelected are: M.A.Hutchins, and J.C.Schelleng. Together witn incumbents F.B.Clough, W. J.V.Doraaleski, R.E.Fryxell and F.Lewin, these constitute our Board of Trustees which was increased to a total of 12 in 1972. Regretfully, and after considerable thought, the Board voted to increase the annual membership dues to beginning January 1,1974. Not only are printing costs continually increasing but also mailing costs which are scheduled to go up again in January 1974. We again urge those of our members wno have not paid their 1973 dues ($5.00) to do so promptly. On September 2, our "Secretary was forced to send out second notices to 149 members nearly a third of bur membership. Our treasury does still have a balance, but far from—sufficient to cover the expenses of this Newsletter and other commitments during the winter. To cover increased costs, we also are forced to raise our charge for back issues of the Newsletter to per issue. COPYRIGHT Catgut Acoustical Society,lnc. 1975

CONCERTOF OF

' Brunswick,

first Council

School Erie,

Obsrlin State Contrabass

"Statements for G. Gordon Alto, Tenor,

Alto,

Carl Contrabass

Alto, Snail Contrabass

followed, R.H.Scanlon, Creel,

$8.00

$2.00 2

CATGUT ACOUSTICAL SOCIETY President Stewart Hegeman 176 Linden Avenue Glen Ridge, N. J., o7o2B Vice President Virginia Apgar 30 Engle Street Tenafly,N.J.,o767o Vice president Lothar Cremer Tech . Univ . Berlin 1 Berlin 10 Einsteinufer 27 Germany Secretary Carleen Hutchins 112 Essex Avenue Montclair,N.J.,o7o42 Treasurer Dugald McGilvray 12 Clairidge Court Montclair,N.J.,o7o42 Editor Robert Fryxell 7355 Drake Road Cincinnati Ohio 45243 Mr. and Mrs. Donald Blatter, June 1968 taken in the yard of the Hutchins* home, Montclair, New Jersey

On June 26, 1 973 y Simone Fernando Sacconi, dean of Italian violin makers in the USA, died* Known throughout the world for his meticulous craftsmanship and skill in violin making and repairing, he was not only a great teacher but a warm and enthusiastic person. During the years when I was privileged, through the kindness of the late Rembert Wurlitzer, to make several instruments under Sacconi' s direction I came to realize how deep was his devotion to the violin and its rich heritage in his native Italy, which he had unearthed and documented even to the tools, patterns, and methods of using them* He gave me the pattern of Stradivari's viola, the wooden form around which an instrument is made, and insisted that I use pegs and string instead of clamps in glueing the ribs to the corner blocks, since that was the way Stradivari had done it* Sacconi came to the USA in 1934 and until 1950 was with Emil Herrmann when he became head of the violin department at Rembert Wurlitzer,lnc> He made many instruments himself, among them a highly ornamented copy of one of Stradivari's violins, but it was for his skill and ability in repair and restoration of the early instruments that he will be long remembered throughout the world* Carleen Hutchins Ed: Readers may be interested to read further in a notice which appeared in the Strad for August 1973 the 1000th issue of that -journal! - 5 Plans are shaping up for sending the eight instruments of the new violin family to England early in 1974 so that they can be presented at the Eighth International Congress on Acoustics in July* The committee in England making plans are: Mr. Alan Sleath, Chairman, Dr. Bernard Robinson, Prof. C.A.Taylor, and Mr* Sandy Brown. Dr. Hobinson is arranging for care of the instruments and players for them, Mr. Sleath is planning for their performance over the BBC. In addition several other musical groups are interested in hearing them and possibly composing for them* Funds for the venture are being sought by C.M.Hutchins. Anyone interested in contributing? The Department of Musical Instrument Technology of Newark Technical College in Nottinghamshire, England, is currently conducting a course in violin making and is in touch with tne Catgut Society on several problems of acoustical testing of instruments during construction. The Super Sensitive String Company has moved to Sarasota, Florida (Porter Road, fi.R. #2 Box 30-V). They have made strings for the new violin family instruments and are packaging them under a special label using our logo of the Cat and the Fiddle. Mrs. Frederick A. Saunders has generously made available to the Society Prof. Saunders* records and files. These will eventually be part of the library facility which we are planning to develop in conjunction with the Library and Museum of the Performing Arts at Lincoln Center. This facility will hopefully contain much of the published material on violin acoustics and music for the new violin family so that it will be available for general circulation in copy form. An article on the PHYSICS OF BRASSES by Arthur Benade which appeared in the July issue of Scientific American has received a great deal of favorable comment . The November issue of the Music Educators National Conference Journal will carry THE BOWED STRINGS, YESTERDAY, TODAY, AND TOMORROW by Carleen Hutchins and Marjorie Bram. This presents a musical evaluation of the new instruments of the violin family in historical context with comments taken from the speech made by Frank Lewin at the Washington D.C. concert in 1970 for the Acoustical Society of America. The September issue of the Audio Engineering Society carries an article by C.M.Hutchins "Methods of Violin Testing* which is a survey of the different approaches and equipment that have been used by researchers over the past two centuries in trying to unravel the intricacies of the violin.

The Division of Continuing Education at the University of Hew Hampshire (Durham) will conduct a special summer program on the making and repair of stringed instruments during the summer of 1974« The program is being planned in cooperation with The Mittenwald School of West Germany, the Catgut Acoustical Society, the Hew Hampshire Commission of the Arts, and Strawberry Banke,lnc. of Ports- mouth, New Hampshire* The summer program will consist of two one-week workshops entitled "Elementary Workshop in the Repair and Maintenance of Stringed Instruments,'" scheduled for July 8 to 12 and repeated the following week, July 15 to 19* Each workshop will .provide 30 hours of instruc- tion from Mr. K. Roy, Director of the Mittenwald School of West Germany. The University will supply each student with a basic tool kit which will become the personal property of the student. In addition to lectures and discussions, students will have an opportunity to work on their own or other stringed instruments during the workshops. For more information about the summer program, contact Edward J. Durnall, Director of the Division of Continuing Education, University of John Schelleng and Bobert Pryxell New Hampshire, Durham, N.H. 03824. at the Hutchins' summer camp Telephone {603) 862-2015. in New Hampshire, July 1973 4

Anne Cole of Albuquerque, New Mexico has made two tenor violins and one vertical viola. These have already seen much use in public performance such as in the notice which follows:

9fcc S£os JWawos cA/tte Council! Anne David vertical viola violin tenor violin presents Kenneth Cooper, piano

Cfcawbe/t t^Uustc Sunday,May 7:30 pjn.

Fuller Lodge, Los New Mexico with oWew

PROGRAM PROGRAM NOTES Joye Johnson is a composer and pianist from. Albuquerque who was Arioso J°ve Johnson askedasked to write for the vertical viola and tenor since there is almost no original music these two instruments. The pieces which will hear in A Major, Op. 100 Johannes Brahms tonightcan be described as being melodiouslyatonal and the that olot Allegretto grazioso small kernels of musical thought loosely and sometimes contrastingly strung together. The Arioso vertical viola is rather with an Allegro running throughout.II li Opposite ...in character_..u, is the darkmoodlIIUUU lUI 5 - tenor which thrusts itself upon the- listener in a bucolic, boisterous manner. Allegro Joye Johnson Brahms was chosen as theother composer through which the vertical viola and tenor violin could be demonstrated since his music is Op.posth JohannesBrahms with that intense lyricism and great tonal so well expressed on a string instrument. The third movement the violin sonata in A major transcribed viola by Harry Robin is particularly well suited 111 presenting the vertical viola due to its low rich melodyon the G string. The Sonatensatz or Scherzo is a single movement originallypart the F.A.E. i- a conipubiiecomposite work uyby Dietrichuwuimi and Brahms written .v., Discussion otnvionn waningLjn. vio|jpjst Joachim , n this pjece the ,en0r is exhibited as an instrument possessing the more brilliant tonal qualities the violin rather than the mellow sound thecello. The trio in E major is actually intended part8 dl:>u dllbl Mueu cello or INTERMISSION norn andana P'apiano;n°. butDUI lnethe horn P " is also transcribed- """ viola'bythe'composer. Thecello part is written almost entirely in the tenor which means that the is excellently positioned the tenor violin. It is hopedthat as well as Brahms will enjoy this new aberration IV a superior piece of chamber music.

Major,Op. Johannes Brahms Trio in E-flat 40 pianist, recently work at AndanteAnriantP Kenneth Cooper, a Los Alamos retired in teaching and Allegro the lab and is now a full time musician engaged private a Anne reside in Adagio mesto performance. David Los Alamos product, and they have a cello students. Allegrocon brio Albuquerque where class violin and

Frede Christensen of Laxa, Sweden, has finished construction of a soprano violin and vertical viola, and has also started a baritone violin. He suggests playing all sizes of these instruments in "da Gamba" position so that the left hand will be in a more natural position and thus tire less easily. For this purpose he recommends a special holder "XSi!_LX£".* shouldor-chinrost for sizes smaller than the vertical viola (see Figure) in order to eliminate rubber bands damping caused by squeezing the ribs attaching with the knees. This holder is a com- to corners bination of a "Menuhin" type plus a pedestal to be gripped by the knees.

Cole, Cole,

6,1973

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BOOK B E V I E V The Foundations of Acoustics "by Eugen Skudrzyk The next eight chapters are devoted to the solutions of the wave equation in cartesian, cylindrical, Springer-Verlag and spherical coordinates, including various sources New York, 73 ma, 1971 and guided waves in channels and tubes* 790 pages, price Chapter 22 solutions in spheroidal longest and probably on wave coordi- This book ia one of the nates may be the only such treatment in textbook the most expensive on the subject yet published form. An exhaustive, classical treatment of scatter- of acoustics. To some the title may suggest an diffraction the book concludes the bread ing and and elementary- introduction to range of with chapters radiation of sound from membranes the on topics identified as acoustics by Acoustical arrays, Green's definitely not elemen- and solutions using and Society of America. It is self and mutual radiation impedances. tary, the book is heavily mathematical, and the coverage is not broad in the usual sense. Hot Of other texts in English, Morse and Ingard»» even mentioned are familiar terms such as decibel, "Theoretical Acoustics" is most similar in coverage, reverberation, and difference tones. However, it however there are great differences. Skudrzyk is a book of great value to many serious researcher* purposely omitted discussion of sound radiators and in the field. excitors such as strings, bars, and plates. The omission of problem sets was also deliberate. These More guidance is offered by the subtitle, subjects and other topics in applied acoustics "Basic Mathematics and Basic are Acoustics"', for it "promised for future publications. Non-linear be personal effort acous- seems to essentially a highly tics is another topic not covered. favor- in orderly, readable fashion Skudrzyk, to set down an the ing classical Green's of treatments, avoids the function mathematical background and full exposition approach so pervasive in the other book. Skudrzyk is many problems in solutions of difficult acoustical more comprehensive on those topics he chooses to scattering. The effort is radiation and successful treat, and he includes an extensive discussion of as the book constitutes an encyclopedia cf solutions signal analysis and processing which is absent in least scalar in of at the wave equation homogeneous Morse and Ingard. The lengthy bibliography is espec- media. ially valuable as it lists numerous original works After a preliminary chapter on units (electrical), in German. the necessary mathematics are developed:; complex analytic Fourier analysis, The cost is shocking, but if the price holds it notation, may be tomorrow's bargain. To one in need its. correlation proba- of integral analysis, wealth' of information the book is worth its price bility, and statistics. Filtering, transfer func- today. signal processing also tions, and are discussed Daniel V. Haines before the subject of acoustics formally enters in Chapter 13 on sound.

Two of our***********members have recently published*********doctoral dissertations: F.L.Walter Reinicke - Die ffbertragungseigenschaften dcs Streichinstrumenten- stegea — Technical University of Berlin, Ho.D-83, 1973 Erik V. Jansson On Plane and Spherical Waves in Horns with Ron-uniform - Flare I. Theory of Radiation, Resonance Frequencies, and Mode Conversion. 11. Prediction and Measurement of Resonance Frequencies and Radiation Losses. Case-Western Reserve University, Cleveland. Co-authored by Prof .A.H.Benade and published by Speech Transmission Laboratory, Stockholm, Mar. 1973 An excellent book has also been published recently by Juan G. Roederer: "Introduction to the Physics and Psychophysics of Music" - Volume 16 of the Heidelberg Science Library (Springer-Verlag, New York). Also recently published is "Electronic Simulation of Violin Resonances" by M*V.Mathews and J.Kohut in J.Acous.Soc.Amer., V01.53, #6, 1973, pp. 1620-26. ******************** Several of our readers have suggested that we start a question and answer column in these pages. An excellent idea! Questions will be published in thenex# issue after receipt, and readers who have answers will be encouraged to respond directly to the questioners or to the editor. Answers to questions of general interest will of course be published. When sending questions, please include your mailing address!

$75.20

follows, functions,

functions, transforms, Last spring, the American String Teachers Association bestowed the Artist Teacher of the Year award to a bassist for the first time. The recipient was Catgut member David Walter of New York. Robert Jones, whose article appears later in this issue, was featured in two-page spread plus cover photo in the July 18 issue of the Los Altos (Calif.) Town Crier. In the last Issue we reported on the accomplishments of Dr. Henry James in making a large variety of pre-violin stringed instruments. Even as we wrote about it, he was moving from Florida to Oregon. His new address is: 15685 S.W. Village Lane, Beaverton, Oregon, 97005. In the Strad for May 1973, M.B.Stanfield reports on an interesting concert held March 11 at the Newark (N.J.) Museum, conducted by Marjorie Bram. The concert was in memory of Russell B. Kingman, whose collection of ancient stringed and wind instruments was featured in a broad range of early music, particularly of the 17th century. Society, Composer Robert Haskins, on commission by the Catgut Acoustical Orchestra has completed a new work "Variations for Solo Viola and Chamber . The International Congress on Acoustics will meet in London during the period July 23-3t, 1974. A few weeks ago, Dr. Virginia Apgar and Prof. Lothar Cremer met in Berlin to continue making plans for a technical meeting of the Catgut Acoustical Society to be held the week preceding the ICA at the Mittenwald School of Violin Making (Germany) July 15—19* Preliminary notices of this— meeting to some of our members have already drawn affirmative responses from 8 USA and 19 European members. There has also been discussion of the possibility of a Catgut meeting in England at the time of the ICA, although definite plans are not available at this time. Anyone interested in information about either of these meetings should contact the Secretary as soon as Hutchins and David Rubinoff Carleen possible, since reservations, espe- University, Oxford, Ohio Miami cially in Mittenwald, must be made March 1973 well in advance.

In late April, Carleen Hutchins lectured to the Smith College Departments of Physics and Music. The new instruments were demonstrated in a public lecture and a seminar discussion of the basic principles in violin acoustics followed. The Physics Department is planning a course in musical acoustics. In May, Morton and Carleen Hutchins went to South Carolina for a series of conferences with Dr. Daniel Haines (Columbia) and Dr. Hiram Curry (Charleston) on problems of materials testing pertinent to violin construction. Five of the instruments of the new violin family were used at the Yale Summer School of Music and Art in Norfolk, under the supervision of Broadus Erie and Aldo Parisot. The Friday violin making and testing sessions at the Hutchins* home in Montclair, New Jersey were attended by an average of six to ten people last winter, some on a regular basis and others as their work warranted. The sessions will continue for the coming winter season.

Conn, 7

ACOUSTICAL TREASURES AT THE ROYAL INSTITUTION IN LONDON Charles Taylor, University College, Cardiff, U.K. About two— years ago I was privileged to give the Royal Institution Christmas Lectures under the title "Sounds of Music". The aim of the series was to present the underlying Physics involved in the production and transmission of musical sounds, in- a way that would be amusing and understandable to those with no background in science, and also acceptable to those with an appreciable knowledge of Physics. The Christmas Lectures have been an annual event since 1826 when Faraday was the Director and his classic phrase to describe their level was that they should be "directed to a juvenile auditory". During a recent visit with Carleen Hutchins I was recounting some of the experiences we had during the preparations for the series and she suggested that I might write about them for the Newsletter; hence this note. The Royal Institution was founded in 1799 "by Count Rumford, who, incidentally, was born Benjamin Thompson in Massachusetts of English parents. He sided with the Royalists in the War of Independence and escaped to England from Boston in 1776. Hia proposals were "for forming by subscription, in the Metropolis of the British Empire, a Public Institution for diffusing the knowledge and facilitating the general introduction of useful mechanical inventions and improvements, and for teaching by courses of philo- sophical lectures and experiments the application of science to the common purposes of life". (1) Sir Humphrey Davy worked there for many years; Thomas Young did his work on the wave theory of light in its laboratories; Michael Faraday, who was the Director for many years, did much of his basic work on electricity there, and indeed an impromptu lecture given by him is believed to be the inspirational source of Clerk Maxwell's electromag- netic theory. One of its main purposes has been to present science to the public and a great tradi- tion of clear sind lucid explanationswith superb lecture demonstrations has grown up over the years. There are endless corridors and basements which house priceless mementoes of some of the great demonstrators of the past. In particular, in the area of acoustics Professor John Tyndall (Resident Professor 1867-1887) provided many delightful experiments and his book "On Sound" (2) published in 1867 gives graphic accounts, many of which are illustrated by woodcuts. Figure 1 shows one of these. I decided at quite an early stage that I should like to U3e this particular piece of apparatus and asked Mr. William Coates the man who prepares all the lecture demonstrations- and is in general charge of all the apparatus if he could make the necessary equipment- and his reply was "Why make it - we have it!", and sure enough after a brief search in the basement we found the exact equipment from which the woodcut had been made. This became a familiar pattern and in two or three instances we found the precise equipment portrayed in woodcuts and I had many fascinating searches which brought to light treasures from the past. The original models in cardboard and clay which were used by Sir Richard Paget in his early work on the voice and particularly on the formants corresponding to vowel sound3are preserved there. The various sets of tuning forks collected by Charles Wheats tone to demonstrate the musical scales current many (2) in different Eastern Woodcut from Fig. 94 of Tyndall 's "On Sound" countries are still in existence as are some of the concertina-type instruments which were designed and made by Wheatstone to play in the various temperaments. One piece of apparatus which we used in the series is the device known as Goolds generator which is a slab of steel about 60 centimeters long, 15 centimeters wide and one or two centimeters thick which when supported and stroked with a rod of cane emits a powerful and penetrating note as a result of transverse vibrations of the massive plate. Among many other exciting experiences it was a strange feeling to use in one of my demonstrations a ripple tank which is confidently believed to be the one actually used by Young in his work on the wave theory of light; certainly in design it is identical 8

with the drawings of Young's apparatus. And so we could go on. But perhaps the most delightful treasure of all is merely a hole in the floor! The hole was made, by John Tyndall somewhere roundabout 1860. It is now filled with a removable plug and the, idea of the experiment was to insert a long wooden rod some '1 to 2 centimeters in diameter through this hole and right down into the basement where the lower end rests on a piano sound board. The other end projects about a meter above the floor in front of the lecture bench and wadding is packed round the rod where it passes through the various floors so that sound is not transmitted by the air but at the same time the rod itself is not in rigid contact with the surrounding floor. A pianist in the basement playa and practically no sound can be heard up in the lecture theatre. The body of a violin, cello, or harp is then placed in contact with the top end of the rod whereupon the piano music can be heard throughout the lecture theatre. The quality of the sound, however, varies with the particular instrument used and hence we have a splendid illustration both of the amplification-effect of the body of the instrument and also of the formant characteristic which is imposed on the sound. When we repeated the demonstration in January 1972 we had one advantage that Tyndall could not have had the BBC were able to provide split screen television pictures so that it was possible to- see that the pianist really was playing the piano and simultaneously to see whether the cello or violin was actually in contact with the rod or not. I think the excitement that we felt at being able to reproduce this classic demonstrationis matched only by Tyndall *s own enthusiastic account which I quote here in full. "What a curious transference of action is here presented to the mind! At the command of the musician's will, the fingers strike the keys; the hammers strike the strings, by which the rude mechanical shock is conver- ted into tremors. The vibrations are communicated to the sound-board of the piano. Upon that board rests the end of the deal rod, thinned off to a sharp edge to make it fit more easily between the wires. Through the edge, and afterwards along the rod, are poured with unfailing precision the entangled pulsations produced by the shocks of those ten agile fingers. To the sound-board of the harp before you the rod faithfully delivers up the vibrations of which it is the vehicle. This second sound-board transfers the motion to the air, carving it and chasing it into forms so transcendently complicated that confusion alone could be anticipated from the shock and. jostle of the sonorous waves. But the marvelous human ear accepts every feature of the motion, and all tho strife and struggle and confusion melt finally into music upon the brain.? There is a suggestion that during the International Congress on Acoustics which is to be held in London in 1974 it may be possible to hold a meeting at the Royal Institu- tion and to bring out some of these treasures. I sincerely hope that this will be possible as they are worthy to be shared with acousticians all over the world. References.

l.'The Royal Institution, A History by Thomas Martin first published 1942, 3rd revised Edition 1961, published by the Royal Institution.

2. On Sound by John Tyndall, first published 1867, sth edition published 1895 Longmans, Green and Co. London.

THE STRUCTURE HAIR — Robert Fryxell As recently as 1959 when Hoda published his well-known book "Bows for Musical Instruments the Violin Family", the only discussion of bow hair structure (pageß 76-80) which he could locate in the literature was taken from an article by which appeared in the in October 1915. This presumably is the origin of the commonly held view that horse hair has a sawtooth surface, and that this surface allows rosin to stick. Further, it is the wearing away of this surface that allegedly leads to the need for rehairing. Retford however (Bows and 1964, pages 20-21) disputes Scott's comments and states that under the microscope, horse hair has the appearance of a smooth polished rod. Rosin, he says, is capable of sticking to the hair even without a surface such as that described by Scott. Unfortunately, Retford does not his position with photographs.' To settle this disagreement, a specimen of the best quality Siberian horse hair especially selected for bows was examined in the scanning electron microscope*. This specimen was a nominal 0.009 inches in diameter. Conditions examination were: carbon shadowed, 20 kv beam. Four photographs are shown on the next page. The first three were taken at the same viewing angle, 53° off of the axis of the hair. The fourth photograph shows the hair axis horizontal. Clearly these photographs support Retford's description. It is difficult to explain Scott's illustrations reproduced by Roda which show a sawtooth surface. As a matter of fact,- his illustrations-look more like drawings than photographs. Probably they are an artist's interpretation which is not as accurate at it should have been. * The expert technique of is gratefully acknowledged.

OF BOW

Scott STRAB

Bowmakers,

defend

I,B,Miller #3 2G251 #4 ■'

9 10

THE CALCULATION OF THE SOUND DIRECTIONAL CHARACTERISTICS OP THE VIOLIN BODY WITH A GIVEN SOURCE DISTRIBUTION by Y. Nagai, Institute for Technical Acoustics, Tech,Univ.Berlin* 1 . Introduction It has been considered difficult to calculate the directional characteristics of several sound sources vibrating with respective amplitude and phase on a relatively large body such as a violin, piano soundboard,flat speaker, multiway speaker system, etc. One could not easily obtain satisfactory calculated results because of the shadowing effect of each sound source together with the whole body. Directional characteristics of the violin have been examined previously by several investigators such as Olson (1;, Meyer (2), etc. However it still remains difficult to tell which kind of vibrational mode may cause a certain directivity* Therefore it is almost impossible to find a way to feed back these kinds of research to instrument making even if we should know favorable directivities of the violin. On the other hand, with the recent development of holographic techniques, for example, it has become possible for us to determine the vibrating mode, including amplitude and phase. Figure 1 shows one example of a violin body vi oration obtained by Reinicke (3) with the holographic method. Once a sound source distribution is known, a next step would be to calcu late the directional characteristics. This will be shown in this report, as suggested by L.Cremer. 2. Theory When the body form, the positions of sound sorces located on it, and the frequency are given, the shadowing effect of amplitude P and that of phase cp concerning one of the sources are written as : P - p(#) $ ■ 9(0) where 0 is the angle in a plane observed (in degrees from 0° to 360 ) Letp(o) mean specific amplitude, so p (0°) ■ 1.00 is taken as the standard* The phase value of the source No. k 9-^(0) should be the phase difference from that of selected source, for example, No.l *?]($)" Namely 9^(0) « 9^(0) ~ where 9^(0) means the direct value from the measurement* If once these p(0) and 9(0) are known, we can calculate the directional characteristics with n-sources in the following way. When we let q^. be the volume flow amplitude of the source No.k, the sound field of it dk is written as follows:

k« 1 d-j 4 F (0) [cos j - 1 1 9j(0) + sincp-jCtf)' k- 2 d 2 q (o)rcoscp (0) j * 2P2 2 + sinep2(0) k* n d cosc (0) n " Vn'^ [ Pn + 3 sin9n(0)] then the total sound field dtot(0) will be * Present address! Electronic-acoustical Department, Nippon Gakki Co.Ltd., Hamamatsu, 430 Japan 11

back—plate

Tig. 1 Hologram the violin at 873Hz,where q means relative amplitude

Fig.2

Fig.3

d (o) (^) cosCp sinep tQt Vk k^) + (0) (0) - gi O^ i\Pk k from which we obtain the directional characteristics D(0) 2 2 »(0) w) cosep W] + (^ 9incpk^)] - J[h Vk K [r: Vk To verify this theory by experiment, we took a rectangular box on which eight loudspeakers were disposed symmetrically as shown in Fig.2, because such a system has an advantage of simplicity in data input to the computer. That is to say, with only one set of the measured values for p(0) and 9(0), the computer can read all necessary data as to each source. P(0) and 9(0) were measured at 873 Hz in the plane which contains two central axes of the rectangular box as shown in Fig. 3* The result of this measurement is shown in Fig. 4, from which we could calculate the directional characteristics D(0) through the computer program in Fig. s. For the different amplitudes and phases of each source, we could easily compute additional results.

of 12

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Results In the setup in Fig.2 the amplitude of each loudspeaker could be controlled independently and the phase could be fixed in either 0 or 180 at the criterion angle, which is distinguished by the + or sign put before the figures in -Fig*6. In this table, the samples q(k) taken In this work are shown* The comparison between the calculations and the measured directional characteristics are shown in Figures 7-12:- The agree- Fig. 6. Amplitude taken in the experiments. ment is considered satisfactory for trie present. Fig. 12 corresponds to the real directivity of the violin vibrating in the manner of Fig.l.

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DO I*l,B CONTINUE HW=SaCT!RR*..P,*XX*XXI OKI TU, ,F .0, ,F5.01 I//////1 CONTINUE CONTINUE Fig. 8 CASE 2 experiment Fig. 7 . CASE 1 experiment calculation calculation

Fig. 9 CASE 3 experiment calculation calculation

4*Conclusions As for amplitude distribution, the directional characteristics can be obtained by the calculation using measured values of p and cp for each source. Especially, in the case of the symmetric system, one set of input data for p and cp is enough to carry out the whole calculation.

13 14

Fig. ll CASE S experiment Fig. 12, CASE 6 is to correspond with the calculation .which directivity of the real violin at 873Hz.

With further use of these computations, it will also be possible to determine the amplitude and phase distribution which gives a desired directional characteristics pattern. Moreover, with further development in finding the relationships between instrument structure and manner of vibration, it may be possible to feed back the result to instrument making. References: 1) Olson,H.F., Music Physics and Engineering, Dover, p*232 2) Meyer, J., Die Richtcharakteristiken yon Violoncelli, Instrumentenbau-Zeitschrift, Ho. 19, p*2Bli, 1%5 3) Reinicke,W. Application of Holographic Interferometry to Vibrations Cremer,L. of the Bodies of String Instruments, J.Ac.Soc.Amer., 48 Ho.4* 1970 4) Cremer,L., Me Geige aus der Sicht dcs Physikers, Yandenhoeck & Ruprecht, GSttingen, Dec. 1971 7T *7T "7T *7v "7P *7v "TT 7T A SIMPLE VIOLIN OSCILLATOR - RobeRobert T. Jones For acoustic tests the violin may be driven laterally at the bridge by a small speaker of the type commonly found in pocket transistor radios. To reduce the radiation from the speaker itself I remove the cone, leaving the small voice coil supported by the corrugated diaphragm under the cone. A narrow (half inch diameter) stiff paper ( IBM card paper) cone is then made and cemented to the voice coil projecting forward. At the tip of this cone a narrow strip of fiber is cemented. The fiber strip extends forward an additional half inch or so and can be inserted under one of the strings (A or D) at the top of the bridge. All of this is made possible by a marvelous substance known as "five minute epoxy". The flat base of the speaker is secured to its mount by a type of "double-sticky" tape known in model airplane shops as "servo-mounting" tape. With the fiber strip clamped between the string and the bridge and the driving current from the oscillator turned on it will normally be found that the voice coil is off center. This is easily corrected by small adjustments of position, but it is essential that such adjustments be permitted by the mounting. I use the type of mounting used by machinists in setting up a dial gauge (see photograph) though there are other possibilities. In order to record the driving force I place a four

tt ohm resistor in series with the voice coil and measure the voltage drop. Though these speakers cost only a dollar or two, it seems safe to assume that Faraday 1 s laws still apply, and that the magnetism is of the same quality as would be obtained in a more expensive arrangement. For saw tooth excitation I use the sweep voltage of an oscilloscope. By turning the frequency down to one or two cycles per second one can obtain an impulsive or "delta function" input. For pure tone excitation, a Hewlett-Packard audio oscillator is employed and the sound is picked up by a G.R. sound level meter. Figures 1 and 2 show sound level peaks in the range above 74 db from two violins, one I made in 1956 and the other more recently. The tests were made in a rather reverberant room, making it necessary to interpret the higher frequencies more or less statistically. These violins were made following early recommendations of Prof. Saunders and Mrs. Hutchins, and they have large amplitudes in the low frequency range.

Response to pure tone excitation O.H. Sound level Meter

15 Although both violins have a powerful tone and easy response, the first one is judged not acceptable because of too much emphasis in the bass region and because of a "nasal" quality. It will be noted that in this case the overtone peaks are highest in the 1500 cycle region, corresponding to the observation by Meinel (J.Acous*Soc.An_er., v01.29, July 1957) that overtones in this range produce a nasal quality. In order to test Meinel'a statement more specifically, I arranged to mix the tones from two audio oscillators and played them through an ordinary loudspeaker. My son and daughter, who have considerable musical experience and who did not know the expected outcome of the experiment, definitely preferred 500 plus 2000 Hz to the combination 500 plus 1500. Actually (as mentioned for example by Meckel in Die Kunst dcs Geigenbaues) the nasal range is probably between 1350 and 1700 Hz. My tests in which various distorted wave shapes were played through a loudspeaker both with and without an LC filter centered in this range tend to confirm this im- pression. It will be noted that the second violin has accentuated overtones in the 2000 to 3000 Hz range, the main body resonance is at 450 Hz, and the air resonance peak is somewhat lower in amplitude. This violin is preferred by musicians who have tried both. Production and interpretation of Chladni patterns To calculate the sound radiation from a violin one would like to know the-vibration amplitude as a function of position over the top and bottom surfaces. The holographic technique permits this, but not everyone has access to such equipment. Gross patterns of the vibration modes can be obtained very simply however by the old-fashioned Chladni method. The fact that the violin plates are curved introduces some difficulty and most powders will be influenced too much by gravity. The pictures shown were taken with the aid of pumice powder which seems to have just the right amount of "stickiness" and will flow" uphill away from a vibrating area. At 390 Hz, it will be noted that a portion of the back plate opposite the bass bar is vibrating. This vibration is evidently being communicated through the ribs and is doubtless just in phase with the vibration of the top. Following John Schelleng's analysis (Newsletter N0.16,N0v.1971) it can be seen that this motion of the back plate, far from adding to the sound, will actually subtract from 390 M% it, since it subtracts from the volume changes of the violin. The pattern at 1300 Hz is remarkably symmetrical. It is tempting to associate the perfection of visual symmetry in these vibration patterns with acoustic perfection of the violin. A little thought will show however that the sound radiation might well Hjs be enhanced if the Chladni 1300 pattern were not so symmetrical.*

16 17

NOTE ON J. M. C. DUHAMEL' S MEMOIRE ON THE BOWED STRING (Memorandum of the Academy of Sciences, Paris, Vol.B, 1841) Robert T. Schumacher The credit for first elucidating the kinematics of the bowed string is- usually given to Helmholtz, for he did indeed write out the equations describing the time evolution of the shape of the string. However, credit for perceiving much earlier most of the essential elements of the motion belongs to J. M. C. Duhamel, who published his "Memoire sur I'Action de I'Archet sur les Cordes" in Comptes Rendu in 1841, some 25 years before Helmholtz. (Casual inspection of the English translation of Helmholtz'a great work "The Sensations of Tone" shows no evidence he knew of Duhamel 's contribution). Duhamel is known to students of thermodynamics for *Duhamel's Heat Theorem"', and to students of mathematics for a theorem in elementary calculus. He is given credit in Scribner's "Dictionary of Scientific Biography" for his work on the bowed string and for independently proposing that the ear is insensitive to relative phase, a notion promoted by Helmholtz and usually known as "Ohm's Law of Hearing". Duhamel's Memoire is in two parts. In the first he investigates the motion of the string stretched between two immobile supports when plucked, and when driven by a sinu- soidal force. He also derived the transverse force exerted by the string on the supports. All of this was done analyticallyusing the techniques developed for mechanics by Poisscn, and is described by Duhamel as a necessary prelude for his discussion of the problem of principal interest, the action of the bow on the string. Yet, curiously enough, the second part of his Memoire contains no formal mathematics. It does demonstrate, however, some very perceptive insights into the problem, and describes some experiments of more than passing interest. The state of the understanding of the bowed string problem in 1841 can be gauged by the fact that Duhamel found it necessary to cite, in order to refute, Daniel Bernouilli's explanation of the phenomenon. Bernoulli! had excited the oscillations of a rope with the periodic impulsive force produced by a toothed wheel, and had succeeded in exciting the various normal modes (harmonics) of the system when the rate at which the teeth struck the string equalled the various harmonic frequencies. Prom this Bernoulli! leaped to the conclusion that the "bits of rosin attached to the hairs of the bow perform the function of these teeth" in that they plucked or struck the string periodically, thus producing the oscillations that the body of the violin turns into sound. One can't help but speculate that this notion survives in some form today, at least in the frequent references one sees to the barbs or "teeth" horsehair is supposed to have. (See Roda, "Bows for Musical Instruments of the Violin Family", p. 78 for an artistic rendering of something that has never appeared in the eyepiece of my microscope!)* Duhamel made the following contributions: 1) He perceived the oscillations to be of the "slip-stick" variety. 2) He saw the necessity of modifying the frictional law of Coulomb - coefficient of friction independent of velocity - as suggested by Morin into a frictional law charac- terized by two coefficients of friction, a velocity independent kinetic coefficient smaller than the coefficient of static friction. (This assumption, because of its mathematical simplicity and fair resemblance to the truth, .is used in most modern elementary physics texts). The importance of this modification is that, in modern terms, it introduces in some fashion a "negative resistance" into the driving force (see J.C.Schelleng, Newsletter N0. 12, page 12, Nov. 1969). The string driven with just Coulomb friction will not oscillate. 3) He had the intuition to see that if the bowing velocity was too large (much greater than the maximum velocity of the string at the bowing point) it was possible that the string would fail to oscillate at all. He checked the idea experimentallywith a "bowing machine" - a wheel rotating with -the rosined edge in contact with the string. His brief description of that device could easily apply to the one built by P.A.Saunders and pictured in J.A.5.A.2, 61 (1937). However, perhaps he deserves no great credit for advanced experimental ingenuity, since that mechanism for exciting oscillations of the string is used in the Hurdy-Gurdy, which was popular as early as the 10th century. However, his perception that the string would not oscillate unless sticking took place was precisely correct for the frictional force law he considered, and his ability to demonstrate the result experimentally with his "Hurdy-Gurdy" can be easily understood in terms of Sohelleng's contribution to Newsletter N0.12 if we only at high assume that the bowing velocities he used the negative slope of the friction force vs. velocity curve was not great enough to overcome the losses in the system.

♦See also "The Structure of Bow Hair" elsewhere in this issue. 18

In some other matters, Duhamel 's intuition lead him astray, although he was motivated to perform one more experiment which he correctly reported, although his explanation was wrong. He believed that at the instant the string begins to slip, at the end of the sticking part of the cycle, the motion of the string is identical to the plucked string (which he investigated in part. I). Thus he missed the "time keeping" aspects of the velocity discontinuity which moves back "and forth from finger to bridge and initiates the slipping part of the cycle with a frequency independent of bow velocity. (In the plucked string two discontinuities move, one in each direction, away from the plucking point after release, and if one believes that occurs one misses the mechanism that "keeps time"). Duhamel then reasoned that the period of oscillation would depend on the bow velocity, being longer for smaller velocities, since the time for the string to be pulled ("plucked," he is mislead to thinking) to a displacement large enough for the restoring force to overcome static friction will be longer, the slower the bow is moved. His mistakes were three-fold: the problem is not static, but dynamic, the motion during the slipping part of the cycle is not the same as a plucked string, and the amplitude of the string's motion is not independent of the bowing velocity. He experimented on a bowed string, and reported, as he expected, a perceptibly lower frequency for slow bow velocity than for the plucked string, and an increase in frequency as bowing velocity was increased. The latter effect might well have been the non-linear one described by Schelleng in J.A.S.A. _s£, 26 (1973): at large amplitudes the length of the string averaged over a cycle is larger than the free string length. Consequently the average tension increases^ with amplitude, and the pitch becomes amplitude dependent. As Schelleng suggests, the effect can easily be heard by tuning down a wound gut cello string a few semitones below C and bowing at various speeds. It seems plausible to suspect that Duhamel produced this effect . in his experiments. It is perhaps not surprising that Duhamel 's contribution has been completely over- shadowed by Helmholtz. The latter produced a result quite specific: the correct description in mathematical language of the motion of the perfect string under the action of the bow. Duhamel' s aim was higher. He undertook to explain the dynamics of the motion, including the nature of the force driving the string. In some ways, his seems to have been the bigger step, although it also seems to have generated no succeeding ones that are remembered.

♦ LONG-TIME-AVERAGE-SPECTRA APPLIED TO ANALYSIS OP MUSIC*— E. Jansson and J. Sundberg 1" Introduction Sounding music is a complex acoustic signal. If we analyze in detail its intensity distribution as a function of frequency and time, obtain an enormous amount of raw data even from a few bars of music. Out of this vast multitude of data we must then single out those which are of direct relevance to our purpose of investigation, and arrange them in a surveyable fashion. It Is also possible to obtain a surveyable set of data If we employ a procedure Involving an automatic selection according to some well

s (1) Blomberg, M. and K. : "Statistisk analys av talsignaler", Thesis work at the Department Speech KTH (1970), in Swedish. (2) Blomberg, M. and K. : "Statistical Analysis ofSpeech Signals", L-QPSR pp. ST 1-8. Acknowledgments (3) Liljencrants, J.: "A Filter Bank Spectrum Analyzer", Technical Report No. 1(1968). The authors are grateful to Mats (4) Liljencrants, J. etat'51-channel Analyzer Spectrum Sampling", Blomberg and Kjell Elenius STL-QPSR pp. of this 1-6. laboratory for their help and re- (5) : "Acoustic Analysis and Synthesis Speech with Applica- design of computer tions to Ericsson Technics No. (1959), p. 76. programs. The work was supported by the Bank of (6) Sundberg, J.: "Formant and Articulation* Spoken and Sung Folia Phoniatrica (1970), pp. 28-48. Sweden Tercentenary Fund, the Swedish (7) c.f. F.: "Darstellung des Sprechverhaltens als Humanistic Research Council and the statistische Tonhohen - und Formantverteilungmittels Swedish Natural Science Research Langzeitanalyse", pp. 1031-1035 in Proc. the Sixth In- Council. ternational Congress Phonetic , Prague 1967 (eds. B. M. Romportl, and P. Janota), Akademia Publ. House (Prague 1978).

♦Previously issued as Report #STL-QPSR 4/1972, Royal Institute of Technology, Department of Speech Communication, Stockholm, Sweden.

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Reference Elenius, of Communication,

Elenius, 4/1970, STL-

for 4/1963, Fant, G. of Swedish", Structure of Vowels", 22;1 Winckel,

of of Sciences Hala, defined principle of categorization. On the other hand, such a procedure may provide oversimplified records lacking the type of information which is relevant to the purpose of investigation. Therefore, it is necessary to explore the consequences of the data selection principle adopted particularly as regards the type of information offered. In this paper this will be made with respect to the long-time-average-spectrum (LTAS) analysis (1,2) when used for the investigation of some problems typically occurring in research on the acoustics of music* 2. Equipment and procedure The sounding music is formed by several factors. The first question to be considered is which these factors are. In Pig. 111-D-1a they are given schematically in terms of a block diagram. The written music is transformed into acoustic signals by the player by means of the musical instrument.- The played music is radiated into the room in a way that may be very complex, and it may be picked up by a microphone and recorded. Conse- quently, an LTAS of recorded music contains the summed information on the written music, the playing, the musical instrument, and the transfer characteristics of the room and the sound recording equipment. The effect of any of these factors can be studied in an LTAS provided that ali other factors are kept constant.

-Written music —* Player —^Instrument -. Room —. Recorder Fig . Block diagram the production recorded music. Fig. 111-D-lb. Block diagram the analysis recorded music. The procedure of analysis is indicated in Pig. 111-D-Ib. The played music transformed into recorded music is analyzed by a filter bank with 51 filters in parallel (3»4)» So far we have used a standard setting of the filters, which provides a good compromisa for gross analysis of speech sounds. In this setting the filters are spaced to give a technical mcl scale as defined by Pant (5)« The filter bandwidths are constant equal to 250 Hz. The output from each filter is rectified and smoothed with a time constant set to 15 msec. The rectified filter output is sampled with a frequency of 160 Hz. This means that several sampling points are obtained even of tones of as short as 50 msec duration. The sampled output from every separate filter is quantized in steps of 1 dB and is added in a storage cell in the computer. Finally, the content of every cell Is normalized with respect to the analyzing time and the LTAS is plotted. The procedure supplies the records with essentially no delay after the sampling is completed. As a consequence of the procedure just described the LTAS is dependent on the fundamental frequencies, the spectrum envelopes, and the intensity levels contained in the sound analyzed. It is noteworthy that tones of high sound pressure level will contribute to the LTAS more than tones of low because of the averaging. Applications For the practical use of the LTAS two questions are important: 1) Under what conditions is an LTAS reproducible, and 2) How sensitive is an LTAS to different factors as the written music, the playing, and the instrument? Most conveniently the answers to these questions can be found by means of experiments. Certain musical instruments generate spectra with frequency regions where the spectrum envelope peaks are rather independent of the fundamental frequency. Some authors speak of formants in such cases. However "formant" is the generally accepted term for a resonance of the vocal tract. Therefore in this report spectrum envelope peaks that appear more or less independent of fundamental frequency will be referred to as constant frequency peaks. It can be expected that the LTAS is an adequate tool for determining the presence of constant frequency peaks in spectra generated by musical instruments. In instruments producing spectrum envelopes falling off at a constant rate as a function of frequency we would expect the envelope peaks of the LTAS to be rather dependent on the fundamental frequencies in the- sample analyzed. In instruments exhibiting spectra with constant frequency peaks, on the other hand, the LTAS would exhibit these peaks more independently of the fundamental frequencies. These expectations were verified by means of a simple experiment. Two series of test signals were synthesized, the first having a constant spectrum shape of -6 dB/oct, whilst the second signal was the just mentioned signal passed through two -resonance circuits. The circuits were connected in cascade and reson- ated at a frequency of 1.5 and 5 kHz approximately. The fundamental frequency was varied in exactly the same way for both types of signals. First, the fundamental frequency was slowly swept from 100 Hz up to 400 Hz, secondly it was swept from 400 Hz up to 1000 Hz and down to 400 Hz again. The shapes of the corresponding LTAS of the two series can be compared in Figs. 111-D-2a and 2b. In the case of the constant envelope shape the LTAS pertaining to the lower fundamental frequency range differs from that obtained for the higher range (Fig. 111-D-2a). In the case of the signal possessing constant frequency

* Methods involving averaging of spectral energy over time have previously been applied to musical sounds by Lottermoser: Instrumentenbau-Zeitschrift (1968), Heft 4 and 5.

111-D-la, of of of of 20

peaks two peaks appear at the frequencies of indicate that cautiousness is needed in the the two resonating circuits both for the choice of test music; preferably the same lower and for the higher ranges of funda- music should be analyzed for purposes of mental frequency (Fig. 111-D-2b). Thus tha comparing instruments. results illustrated in Figs. 111-D-2a and Two performances of the same piece of 2b show that constant frequency peaks can music, every note played in the same way be detected by comparing the LTAS for diff- (detache and fortissimo), in the same posi- ering ranges of fundamental frequency. tion in the room, etc. give the degree of A typical example of a constant frequency reproducibility illustrated in Fig. 111-D-4a» peak occurring in music is the "singing The diagrams show that uncontrollable formant", a spectrum envelope peak near 3 small changes in playing, in the direction kHz present in all vowel sounds as produced and position of the instrument caused by the by professional male singers(6). Pig. player, give minor differences in the LTAS. 111-D-2c gives an example of how this peak This proves that an LTAS is possible to appears in an LTAS derived from a male reproduce with a rather high accuracy. When professional opera singer performing a short the dynamics and the bowing prescribed in song. We observe three major peaks: one the notation was followed (mezzoforte to around 4QO Hz representing a combination piano and generally four notes in each bow) of the fundamental and the first the lower LTAS of Fig. 111-D-4b was obtained. one more diffuse between 1 and 2 kHz corr- The effect on the level of the LTAS is con- esponding to the second formant, and one siderable, while the effect on the shape is rather pronounced peak in the region of the surprisingly Bmall. The result indicates "singing formant". Its high level is due to that the shape of LTAS is fairly independent the fact that it is present, in the same of the way of playing. Performing the same frequency region, in all vowels, whereas piece of music as similar as possible on the lowest two formants vary considerably two different violins gave the LTAS shown in frequency (7)» in Pig. 111-D-4c. In view of the reproducibility demonstrated in Fig. 111-D-4a, the Let us now consider varied signals pro- discrepancies between the two LTAS are duced by one type of instrument, the violin, significant. Thus, fairly small differences in normal playing. As a rule the properties as between various items of an instrument are changed by the player, of a violin not may be detected, provided that the LTAS are only the way in which they are used. There- obtained with the procedure just described. fore spectra of played tones normallyre- flect properties of the instrument. The It should be pointed out that the LTAS study of spectra of single notes is a very displayed refer only to one listening posi- tedious work. Such spectra are difficult tion, and thus do not characterize all prop- to interpret, as the playing can hardly erties of the instrument. For certain ever be controlled well enough to secure a purposes it is advantageous to compute an reasonable degree of reproducibility. A LTAS from recordings made in several posi- higher degree of reproducibility would be tions in a room. By this procedure the offered by averages over several tones as influence of the standing waves of the room provided by an LTAS. Let us first demon- is removed, and the average sound radiation strate a case where the player in fact has in all directions obtained. Preliminary changed the properties of the instrument, experiments with a church organ showed that i.e. by applying a mute. The LTAS of two reproducible LTAS can be obtained from a playings containing the same notes are minimum of five microphone positions. shown in Pig. 111-D-3a, one time with and Similarly we would expect that the timbre the other without the mute. The effect of of some given type of instrument may be the mute is clearly seen in the LTAS. With obtained by averaging the same series of the mute, the energy .radiated is concen- tones played on a sufficiently large num- trated to lower frequencies on each tone. ber of items of that instrument. Note also the additional intensity peak just below 1 kHz introduced by the mute. This 4*Conclusions peak shows that a partial of a played tone In this report we have shown that sub- may indeed be stronger with a mute than stantial acoustical differences, such as without. muting a violin, easily can be seen in an Let us now study how a variation of the LTAS. Furthermore, we have demonstrated a music influences the LTAS. Two samples procedure allowing separation of envelope were played on a violin: a chromatic scale peaks related to the instrument, and peaks and a triad figure, both covering the same related to the fundamental frequencies. octave. The two corresponding shown This is done by comparing two LTAS pertain- in Fig. 111-D-3b, are strikingly similar. ing to different fundamental frequency ranges. Finally we have on the other hand, each octave of a " shown that even two-octave chromatic scale is analyzed quite small but significant discrepancies separately, the LTAS differ as seen in can be detected if all parameters but one Fig. 111-D-3c. By and large the curves are kept constant: written music, playing, are similar.up to 1.5 kHz but at higher room positions, etc. This makes us believe frequencies the higher scale reinforces that the LTAS represents a tool well suited the higher spectrum part. These results for a variety of analyses of music.

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