Feb. 19, 1952 _ A. F. KNOBLAUGH 2,586,664 MUSICAL INSTRUMENT EMPLOYING CONTINUOUSLY MOVING MEMBER Filed July 20, 1948 2 SHEETS-SHEET 1

‘ MWIAWOEMDZ/l IN VEN TOR. BM Gala/74% Feb. 19, 1952 A. F. KNOBLAUGH 2,586,664 MUSICAL INSTRUMENT EMPLOYING CONTINUOUSLY MOVING MEMBER Filed July 20, 1948 2 SHEETS——SHEET 2

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INVENTOR. walla/1w“ Patented Feb. 19', ‘1952 2,586,664 UNITED STATES PATENT OFFICE 2,586,664 MUSICAL INSTRUMENT EMPLOYING CON TINUOUSLY MOVING MEMBERS Armand F. Knoblaugh, Cincinnati, Ohio, assignor to The Baldwin Company, Cincinnati, Ohio, a corporation of Ohio Application July 20, 1948, Serial No. 39,674 13 Claims. (01. 84-118) 1 2 My invention relates generally to musical in between the pitch determining elements and the struments, and particularly to electrical musical wave form patterns in musical instruments of instruments employing continuously moving the photoelectric type wherein beams of light members having a plurality of series of light scan such patterns to produce in a photocell cir openings, magnetic projections or other elements, cuit electric ‘pulsations corresponding to the tones the rate of passage of which past a given point desired. or points determines the musical pitch or fre It is a further object to provide, on a single quency of the tones produced. compact moving member, means for determining In such instruments, wherein a whole gamut the pitch of a gamut of tones in photoelectric or of pitch determining elements is disposed upon 10 other musical instruments. one moving member in an endeavorto provide As a supplement to the above objects, since a structure of practical size, cost, and operation, it is sometimes desirable in a musical instrument there is a problem of providing an applicable to employ more than one moving member, an series of whole numbers for proportioning the object of the present invention is to provide com quantities of elements in respective endless rows 15 pact pitch means comprising two moving mem disposed on a disc, drum, endless tape, or the bers and associated elements. like. The quantities must be so selected that These and other objects of my invention which rates of passage of the elements in the various will be set forth hereinafter or will be apparent rows will approximate the frequencies or pitches to one skilled in the art upon reading these spec or respective notes of the equally tempered scale 20 i?cations, I accomplish by that construction and closely enough so that satisfactory musical re arrangement of parts and in those procedures of sults may be obtained. which I shall now describe exemplary embodi The problem contains two opposing di?iculties. ments. Reference is made to the accompanying On one hand the individual members of ele drawings wherein: ments in a series must be high enough so that 25 Figure 1 is a diagrammatic representation of their relationships can approximate that of the elements of a photoelectric musical instrument notes of the equally tempered scale. On the to which my invention may be applied; other hand, the numbers must be low enough so Figure 2 shows a portion of a pitch disc and that in placing series of elements on a practical associated parts embodying my invention as ap size moving device, the spacing of the elements 30 plied to a photoelectric musical instrument; in a series member must be su?iciently generous Figure 3 shows portions of a pitch disc and a so that inaccuracies of spacing do not deteriorate timbre disc of another form in a photoelectric the musical effects obtained. As an example, instrument; and "noise” in the musical tones is commensurate Figure 4 illustrates the manner' in which my with proportionate inaccuracy of spacing. Such I my invention may be applied to instruments hav proportionate inaccuracy, in any practical fab ing pitch determining elements disposed upon rication and construction, increases as the space two pitch discs. between adjacent elements decreases, thus dic In Figure 1, I have shown in purely diagram tating that the numbers of elements be low, and matic fashion the operating elements of a photo thus the space between them be large. , 40 electric device to which my invention, as later de Another aspect of the. problem relates to an scribed, may be applied. Light from a source I is instrument producing complex tones by the broken into a series of moving beams by slots 2 scanning of wave forms by elements as above, in a disc 3 which rotates at a ?xed speed as de in motion. In such an instrument wherein one termined by suitable driving means, such as a‘ element completely scans a wave form before an . motor M. The beams, condensed as may be re adjacent element carries out its scanning, only quired by a lens system 4, traverse a photocell 5. su?icient spacing of elementsvobtained by using A shutter system, comprising a ?xed element 6 low numbers of elements, will permit use of having an aperture 1 and a movable element 8 adequate size wave forms so that desired wave actuated through suitable linkage members 9 and forms. may be incorporated and satisfactory rep H) by a playing key ll, serves the dual function licas as musical tones obtained. of permitting the beams to pass when a particu ' Consequently, a primary object of my inven lar note is desired, and of con?ning the beams in tion is to provide a relationship of pitch deter such fashion that as soon as one beam completes mining elements in musical instruments, so that its traverse of an integral number of wave form the musical intervals between the tones pro-_ patterns l2, disposed upon a wave form pattern duced approximate those of the equally tem disc l3, concentric with the pitch disc 3, another pered scale, and wherein the number of elements, beam begins to traverse the same group of wave their sizes, and the distances between them are form patterns. within practical considerations. The light source I may be controlled by a stop It is a further object to provide a relationship ?f'l tablet 15 through a switch [8. The photocell 5 2,586,664 3 4 may be connected through an ampli?er I‘! to a ratios according to my invention from the ratios loud speaker It for the production of sound. of the equally tempered scale are sufficiently low The instrument of Figure l is elementary only, to render such ratios wholly satisfactory to the for general explanatory purposes. A complete ear for relating the quantities of pitch determin polyphonic device employing my invention will ing elements as mentioned above. It should also contain pluralities of keys, shutter mechanisms, be noted that the whole numbers in my ratios are and the like for the several notes, as well as plu low enough so that elements of practical size‘ may ralities of rows of elements 2 according to the be disposed in rows, either circular or straight, present invention, as will be set forth below. ‘ of comparatively short length. As implied by In Figure 2 an opaque pitch disc l9 has ar the numbers indicated at the left of the pitch ranged thereon endless concentric rows or series disc IS in Figure 2, integral multiples of the series of transparent slots 20, each row having a whole of twelve numbers may be employed to carry the number of slots as indicated by the series of gamut of tones through more than one octave numbers shown in Figure 2 at the left end of the in exact octave relationships. For instance, if illustrated portion of the pitch disc 19. I have dis ,. the pitch disc I9 is rotated at a speed of 33.83 covered that the series of twelve numbers from R. P. M. (revolutions per minute), so that the row 116 through 219 have a relationship which very containing 116 slots produces a note C in a musi nearly approximates that of the twelve half tones cal scale having a frequency of 65.4 C. P. S. of the equally tempered scale, which relationship (cycles per second) based on a note of A of 440 will hereinafter be described in detail. Similar C. P. S., the row containing 232 slots will produce to Figure 1 the shutter mechanism of Figure 2 a note C an octave above, having a frequency of comprises a ?xed element 2| having apertures 22 130.8 C. P. S. Similarly‘ the row containing 246 respectively aligned with the concentric rows of slots will produce a C#- one octave above the C,# transparent slots 20. The central area of the por produced by the row containing 123 slots. ‘In this tion of the pitch disc [9 is broken away to expose ‘way I can provide a complete musical scale of wave form patterns 23 and 24 which are disposed several octaves as desired, on a single moving‘ upon a timbre disc 25, which is also broken away member. ' for the purpose of showing the relationship be An exemplary‘ set of dimensions for av ?ve tween the angles subtended by individual cycles of octave disc of the type designated at H! in Fig the wave form patterns 23 and 24. A movable ure 2, and rotating at a speed, as above, of shutter member 26 is shown in an elevated posi 33.83 R. P. M., may include the following, given tion, similar to that of element 8 in Figure 1, ex approximately: ‘ posing the aperture 22, through which can be seen three cycles of a wave form pattern and three Inches corresponding slots 20 of the pitch disc I9, illus- ‘* Radius to row of slots, for (1:65.45 C. P._ S. 1.“ 21,44 ' Center-to-center spacing of slots for (3:654 trating the manner in which the patterns are scanned by the moving slots. C. P. S ------_. ____ -g__~..--.,-,_.T Vs I shall now discuss the relationship of the slots Radius to row of slots for C=2093 C. P.- S. “r 6 20 as mentioned above. Under the letter N in Center-to-center spacing of slots for 0:,2093 C. P. S- uns-g1 ------.-.--_.--..--._____ .01 column I of the chart shown below I have listed Radial spacing between, centers of adjacent the above mentioned series of twelve numbers, the relationship of which, according to my in rows of slots _,-___, ______11; vention, approximates that of the equally tem According to my invention, I employ the same pered scale. ' series of numbers to relate the angles subtended. In the, adjacent column II are listed the ratios by individual cycles of wave form patterns. For N/116, thus referring to the lowest in the series." example, the angle A subtended by a single cycle Adjacent to the N/l16 group is a column III of of the wave form, pattern 24 will be related to the corresponding ratios of twelve half tones accord angle B, subtended by a single cycle or the wave ing to the equally tempered scale. The equally form pattern 23, as the reciprocals of the numbers tempered, or equitempered, scale is’ of course the 2 l9 and I30, respectively, which indicate. the num well known scale in almost universal use in which 50 ber of slots. in the rows respectively aligned with the pitches or frequencies of adjacent notes are the wave form patterns. in the ratio of the twelfth root of two to one, Although. I have shown herein wave form pat an incommensurate number.‘ Consequently, the terns of the variable area type, it is understood numbers in column III are in fact also incom that I may also. employ variable density patterns mensurate and only their accurate approxima— well known in the art. tion can be given. Column IV lists the depar In the case of a photoelectric instrument em tures of numbers in column II from correspond ploying a pitch disc and a timbre disc- which are' ing numbers in column III, in parts per 10,000.v not mounted concentrically but overlap as shown 60 in Figure 3, the wave form patterns 21 and 28, I— II—, III— IV— disposed upon a timbre disc 29, will'subtend angles Equally C and D, respectively,- having their respective N N/ll? Tempered Departures apexes' at the center of the pitch disc 30. In such Scale Ratio ‘ an instrument one tone color may be produced, at a time from a single timbre disc by a single 1. 00000 1. 00000 0 65 1. 06034 1. 05946 +8 pitch disc, the timbre disc being rotatable to bring 1.12069 1.12246 —16_ a desired series of waveform patterns into ‘posi 1.18006 1.18921 +4 1. 25862 1. 25992 -—l0 tion for scanning. 1. 33621 1. 33484 +10 If I "so desire, in the interest of employing 1. 41379 1. 41421 '—.3 1 50000 1.49831 +11 70 smaller diameter discs, or for such purposes as 1 58021 1. 58740 v—7 using longer slots 20 of Figure 2, I may distribute 1 68103 1.68179 —5 1 78448 1. 78180 +15v my pitch determiningelements upon two separate 1 88793 1 88775 +l pitch discs, as shown in Figure 4, still, maintain, ing a satisfactory relationship between the pitch I have found that the above departures of the I 75 elements. The distribution of the pitch deter 2,586,664 5. 6 mining elements maybe accomplished in several containing quantities of said pitch elements in ways. First, I may distribute the elements cor the following proportions: 123, 138, 155, 174, 195, responding to alternate half tones on one disc, and 219. placing on the other disc those alternate pitch 4. In combustion in a musical instrument, two determining elements missing from the ?rst disc. continuously moving members having a speed For example, rows on the ?rst disc may contain ratio, of substantially the twelfth root of twoto 116, 130, 146, 164, 184 and 207, and/or integral one, a plurality of rows of musical pitch deter multiples thereof, as desired, with elements in mining elements disposed on both said members, the following proportions on the second disc; said rows on both said members containing quan 123, 138, 155, 174, 195 and 219. In this case the titles of said pitch elements in the following pro discs 3| and 32 of Figure 4 may be mechanically portions: 116, 130, 146, 164, 184 and 207. - coupled by coupling 33 having 1:1 shaft ratio, 5. In combination in a musical instrument, two or the discs may be mounted on the same shaft, continuously moving members having a speed if so desired. Also according to my invention I ratio of substantially the twelfth root of two to may employ two continuously moving members 15 one, a plurality of rows of musical pitch deter having members of pitch determining elements mining elements disposed on both said members, distributed thereon as determined by a series of said rows on both said members containing quan alternate numbers, taken from the above series tities of said pitch elements in the following pro of twelve, in either of the following proportions: portions: 123, 138, 155, 174, 195 and 219. (a) 116, 130, 146, 164, 184, and 207 and/or inte 6. In a photoelectric musical instrument, a gral multiples thereof; or (b) 123, 138, 155, 174, continuously rotating disc having concentric rows 195 and 219 and/or integral multiples thereof. of musical pitch determining, light varying areas, In such a case, where the discs contain each the said rows containing said areas in the following same numbers of elements in the several series, proportions: 116, 123, 130, 138, 146, 155, 164, 174, but in proportion to alternate semitones of the 25 184, 195,207 and 219. equitempered scale, it will be necessary that the 7. In a photoelectric musical instrument, two shaft ratio produced by the coupling or speed opaque discs continuously rotating with substan reducer 33 be substantially the twelfth root of two tially the same angular velocity, said discs hav to one. In yet another arrangement each of the ing endless concentric rows of musical pitch de discs 3| and 32 may contain identical series of termining, light varying areas, said rows on one pitch determining elements arranged as all of the disc containing quantities of said areas in the semitones of one or more octaves, in which event following proportions: 116, 130, 146, 164, 184 and the shaft ratio produced at 33 may be 2:1; 4:1, 207, said rows on the other disc containing quan or other whole number ratio suitable for octave titles of said areas in the following proportions: separation. 123, 138, 155, 174, 195 and 219. Although I have described my invention as ap 8. In a photoelectric musical instrument, two plying to a photoelectric musical instrument em opaque discs continuously rotating with angular ploying rotary discs, I do not wish to be limited velocities having a ratio of substantially the to such structures. My invention may be applied twelfth root of two to one, there being musical to photoelectric instruments employing drums, pitch determining, light varying areas disposed cones, or continuous bands; or it may be applied upon said discs in endless concentric rows, said to instruments employing continuously moving rows having quantities of said areas in the fol members having thereon magnetic tracks, mag lowing proportions: 116, 130, 146, 164, 184 and netic projections or any other pitch determining 207. elements in endless rows which successively and 45 9. In a photoelectric musical instrument, two continuously pass by a given point or points at opaque discs continuously rotating with angular rates which determine the pitch of the corre sponding notes. velocities having a ratio of substantially the twelfth root of two to one, there being musical Modi?cations may be made in my invention pitch determining, light varying areas disposed without departing from the spirit of it; but hav upon said discs in endless concentric rows, said ing outlined the principles of the invention in rows having quantities of said areas in the fol certain exemplary embodiments, that which I lowing proportions: 123, 138, 155, 174, 195 and claim as new and desire to secure by Letters 219. Patent is: 10. The method of relating the frequencies of 1. In a musical instrument, a continuously 55 twelve oscillations to provide substantially the moving member having a plurality of’ rows of musical intervals of an equally tempered scale, musical pitch determining elements, said rows which method consists in relating said frequen containing quantities of said pitch elements re cies respectively in the following proportions: lated to each other in proportions embraced in 116, 123, 130, 138, 146, 155, 164, 174, 184, 195, the following numbers: 116, 123, 130, 138, 146, 207 and 219. 155, 164, 174, 184, 195, 207 and 219. 11. In a. photoelectric musical instrument, an 2. In a musical instrument, a continuously opaque pitch disc having transparent slots dis moving member having a plurality of rows of posed thereon in endless concentric rows in quan musical pitch determining elements, said rows tities proportioned as follows: 116, 123, 130, 138, containing respectively numbers of elements in 65 146, 155, 164, 174, 184, 195, 207 and 219, and the following proportions: 116, 123, 130, 138, 146, a timbre disc located adjacent to said pitch disc, 155, 164, 174, 184, 195, 207 and 219. said timbre disc having a series of wave form 3. In combination in a musical instrument, patterns respectively aligned with said rows, each two continuously moving members having the said pattern representing an integral number of same speed, and a plurality of rows of musical 70 cycles of a wave, each cycle of a particular pat pitch determining elements disposed on said tern subtending an angle equal to 360 divided by members, said rows on one of said members con the number of slots in the row aligned with said taining quantities of said pitch elements in the particular pattern. following proportions: 116, 130, 146, 164, 184 and 12. In a musical instrument of the type where 207, and said rows on the other of said members in a photosensitive device is traversed by a series 4 2,538,664 7 of light beams at rates corresponding respec ‘116, 123, 130, 138, 146, 155, 164, 1'74, 184, 195, tively to the pitch of notes of a musical scale, 20'? and 219 and means for moving said'mem a timbre disc and a series of Wave form patterns hers in whole number speed ratios. disposed thereon, each pattern representing at ARMAND F. KNOBLAUGH. least one cycle of a wave, the angles subtended by single-‘cycle portions of respective patterns of the REFERENCES CITED series being related as the reciprocals of the fol The following references are of record in the lowing numbers: 116, 123, 130, 138, 146, 155, 164,, ?le of this patent: 174, 184, 195, 207 and 219. v 13. In combination in a musical instrument, a UNITED STATES PATENTS plurality of moving members each having a plu Number Name Date rality of rows of musical pitch determining ele 1,998,461 Kucher ______-______Apr. 23, 1935 ments, said rows containing respectively hum‘ 2,014,741 Lesti ______Sept. 17, 1935 bers of elements in the following proportions: 2,075,802 Davis ______1_>. ______Apr'. 6, 1937