Absolute pitch: an unusual type of memory for standard musical scale Słuch absolutny: Niezwykły rodzaj pamięci dotyczący standardowej skali muzycznej Andrzej Rakowski The Fryderyk Chopin University of Music [email protected] ABSTRACT Absolute pitch (AP) is a rare phenomenon, which appears in some musicians, of long-term memory for the musical-pitch standard values. In the present experiment 63 music students were presented with 2 versions of the ‘pitch-naming’ test, dif- fering in time-distances between the subsequent sounds – 4 seconds or 1 second. It appeared that only the 1-second version of the test was effective in selecting the genuine absolute pitch possessors from a group of musicians. STRESZCZENIE Słuch ab so lut ny (ang. AP) jest rzad ko spo ty ka ną ce chą pa mię ci dłu go trwa łej mu zy- ków do ty czą c ą stan dar do wych war toś ci wy so ko ści to nu w mu zy ce. W ni niej szym eks pe ry men cie 63 stu den tom mu zy ki za pre zen to wa no 2 wer sje te stu po le ga ją ce go na „na zwa niu to nu”, róż nią ce się od le gło ścią cza so wą mię dzy dwo ma na stę pu ją cy- mi po so bie dźwię ka mi – 4 se kun dy lub 1 se kun da. Oka zał o się, że tyl ko jed no se- kun do wa wer sja te stu po zwa lał a na efek tyw ne wy ło nie nie spoś ród gru py mu zy ków osób po sia da ją cych słuch ab so lut ny. 1. Introduction The term ‘absolute pitch’ (AP) is used to define a particular, and as yet not wholly explained, feature of long-term auditory memory which occurs in some musicians. People with genuine, full absolute pitch are capable of recognizing in a natural way the twelve pitches of the chromatic musical scale and associating them with the names of twelve semitones of that scale, e.g. C, C sharp (or D flat, equally valid), etc. The musical pitch values of the same name are recognized as identical across all the octaves of the musical scale. In the present paper it is intended to show absolute pitch as an auditory phenomenon of pitch and long-term memory, based on the complete musical interactions of these two elements. The practical aspect of these relations will be shown later in a simple experiment showing how to select the possessors of genuine absolute pitch from a group of musicians. Before discussing in more detail the unusual phenomenon of absolute pitch it seems reasonable to recall some selected notions of auditory psychophysics such as pitch and its relations, and to propose some refinements in their definitions. 129 130 Speech and Language Technology. Volume 14/15 In most dictionaries pitch is described simply as an auditory sensation which enables ordering sounds in a scale from ‘low’ to ‘high’. However, pitch, particularly in music, appears as a much more complex auditory phenomenon, whose various parts in various ways jointly overcome the limitations of auditory memory [1]. Most important here would be regarding the domain of pitch as divided into two symmetrical sub-domains, pitch value and pitch distance. These sub-domains in music divide further, each into two parts. Pitch value divides into natural pitch (earlier ‘tone height’ [2]) and into a series of strictly categorical musical pitch classes (‘tone chromas’). Similarly, pitch distance divides into the natural pitch distance and into a pitch phenomenon which is strictly categorical and most important in music, namely a set of musical intervals [3]. Apart from being important in ‘giving birth’ to various musically meaningful scales of pitch intervals, the pitch distance scale provides material to create another important sub system of human communication, namely that of speech intonation, so clearly shown by Wiktor Jassem [4]; a system with less strict standards but with creative rules and significant distances not much different from those in a system of musical intervals. In light of the above consideration it seems reasonable to connect the notion of absolute pitch with the sub domain pitch value. Here the long term auditory memory shows its most strict performance. The values of pitch standards, usually acquired early in life in an absolute pitch possessor, remain stable and unchanged even when actual music performance (e.g. singing in an a capella choir) allows for some deviations. 2. The kinds of absolute pitch The feature characteristic of genuine absolute pitch is fixing in one’s memory a specific number of chromas, that is, values of musical pitch, recognised with an accuracy of about one quarter-tone, repeated across the octaves, and each of them expressed through specific features of auditory impressions. Full genuine absolute pitch [2, 5] is the fixing in one’s memory of all the pitches of the within-octave, equally tempered chromatic scale. There is evidence to show that the permanent acquisition of all twelve standards of absolute pitch takes place gradually, and that usually the first to be mastered is the set of seven chromas of the diatonic ‘white keys’ scale. Such a clear differentiation of the regularities of the recognition of notes corresponding to black and white keys has been observed in young people who are most probably not yet in the final phase of forming their absolute pitch [6, 7]. But in the case of persons with fully- developed absolute pitch, there are usually no noticeable systematic differences in the accuracy of tuning the pitch of a test note to the internally-fixed standards of the diatonic and chromatic scale. However, while the examples given above could, in principle, concern full absolute pitch in various stages of development, cases of the stable memorising of single notes must be subject to a different qualification. Such cases are quite frequent and result from the practical conditions in which music is learned or practised. One typical example is the memorising by many students of music schools in France of the pitch of the note ‘C’, caused by the use there of the ‘fixed do method’ of Jacques Dalcroze. The ‘fixed do’ method (in the solmisation system of names, do corresponds to the note C) involves the constant referring of all listening exercises to this pitch standard. Another typical Absolute pitch: an unusual type of memory for standard musical scale 131 example is the frequent memorising by some musicians playing string instruments of the note A4, to which they tune their instruments daily by means of a tuning device. Two authors who have achieved a great deal in the study of absolute pitch, A. Bachem and W. D. Ward, qualify these cases as quasi-absolute pitch [2, 8, 9]. The way in which this category is often used has little in common with the normal way in which absolute pitch functions. A person with quasi-absolute pitch treats his memorised pitch standard as a tuning fork. He takes a long-term remembered value of pitch as a starting point in relation to which he can recognise or intone any note, making use of the per- manently-acquired values of musical intervals. This strategy, aiming often to create the impression of possessing full absolute pitch, has its unquestionable virtues, as it leads to perfection in the use of relative pitch (musical intervals) – most important for a mu- sician. However, a person with quasi-AP employing this strategy can be easily distin- guished from someone who has full absolute pitch. The quasi-AP possessor needs always a much longer time to summon any musical pitch not belonging to his standards, while the reactions of a person with full AP are always spontaneous and immediate. A similar situation appears in cases when the pitch model has not been fixed permanently in the auditory memory but is based on different phenomena, such as remembering the tension of the muscles of the larynx for performing the lowest note of one’s own voice scale or the training of the recognition of a certain segment of the natural pitch scale. Any similarity of the results of these procedures to the effect of absolute pitch can at best be termed, pseudo-absolute pitch. Genuine absolute pitch can be encountered, in two variants, namely as active and passive absolute pitch [10]. Active absolute pitch is the most perfect form of this phenomenon. It enables the individual to produce the required pitch, and to recognise musical pitch classes, generally irrespective of the kind of source and timbre of a given sound. Passive absolute pitch does not allow one to produce required pitch, but only to recognise it. Although possessing the basic attributes of genuine absolute pitch (the recognition of individual chromas is spontaneous, and the reception of each of them is connected with an individual, specific auditory impression), passive absolute pitch has many limitations in relation to active absolute pitch. Besides the basic restriction, which is the inability to intone the required pitch, passive absolute pitch usually displays con- siderable sensitivity to the timbre of the notes used in the test. Often, the effect of the absolute recognition of a chroma is limited here to the sounds of one’s own instrument, e.g. the piano or the violin. 3. How does absolute pitch arise? Interest in the phenomenon of absolute pitch dates from the second half of the nineteenth century [11, 12], and almost from the very beginning there emerged two controversial theories accounting for its origins. Meyer [13] was the first psychologist who, in the belief that the acquisition of absolute pitch was a question of training, carried out excep- tionally laborious training on himself and his colleague, ultimately achieving 60% and 64% of correct recognition of notes on the piano.