Absolute Pitch

by Staffan A. Svensson

Have you ever wondered how some people are able to sing a specific note on command, simply tell you "that note is a G flat" or "the key of the song is C"? These people are using something called absolute pitch, and in this article I try to briefly describe what it is, where it comes from and how you probably have some of it yourself, without even knowing it.

Absolute pitch (sometimes called "perfect pitch") contrasts to Relative pitch, and both are used to describe how a person hears notes, or more specifically pitches. These terms are usually used in music, but are equally valid whether you are talking about music, engine sounds or birdcalls.

When someone uses relative pitch, they compare one pitch to another pitch, so to be able to use relative pitch one needs a minimum of two notes (or some other sound with a pitch). When someone hears that a melody first goes up and then down or that the pitch goes higher when an engine accelerates, they are using relative pitch. This type of listening is taught in music schools and is the basis for all types of intervals, scales and chords. Almost all people have some level of relative pitch, and even those who are tone deaf (approx. 4%[1]) are not completely without this ability, even if it is markedly reduced.

When someone uses absolute pitch, they are listening to what frequency a tone or a group of notes have. You only need a minimum of one audible pitch to use it; it is not about comparing it to anything. This has for a long time been seen as a sort of almost magical innate ability to name a pitch or to sing a specific note on command. Some have seen it as a curiosity with little practical significance, while for others it has been the holy grail of music excellence. Lack of knowledge has made the whole concept a well-nourished growing ground for rumours and guesses.

Relative pitch has never been a problem for people to understand. Almost all people hear the difference between a high note and a low note if you play one after the other, and some people do this better than others. No mystery there. But what of this weird absolute pitch? What so few realized is that some people hear frequency differences better than others. In the same way people see the differences in frequency when we see colours, we also hear them (we can only see about one "octave" but a person with good hearing can hear 10 octaves). But everyone that has potential to see colour seems to naturally develop the ability to see differences in colours, while few people seem to hear the frequency differences. Why? Part of the answer, as with many other hard questions, comes with defining what we really mean by the question. If hearing colours means a person can identify tones played on any instrument and name them correctly each time, then very few will qualify. If hearing colours instead means someone can hear that a melody played in one key sounds or feels different in some way, or has a different "flavour" to it, compared to the exact same melody played in another key, suddenly this group includes most people. Such an experience indicates the same kind of ability, only not refined enough to be able to differentiate between and thus identify semitone intervals as standardised in western music.

The American Heritage Dictionary defines absolute pitch as the "ability to identify any pitch heard or produce any pitch referred to by name"[2]. Other definitions include "capacity to identify any tone upon hearing it sounded alone or to sing any specified tone"[3] and "that sense which some people possess of the actual pitch of any note heard"[4]. There exists no word for weaker forms or for this ability as a whole, and this may partly explain why so few people realize the simplicity of the phenomenon.

So why doesn't every person possess excellent absolute pitch? It does not seem as important to us as seeing colours, so even though the ability to learn is innate, practise is required to get it to the level where one can use it in music. Most people do not have that need, so the ability never gets very cultivated. Many have no idea that the possibility exists, and if they do not happen to discover it for themselves they will never even try to develop it. This accidental discovery is probably what causes some children to develop it spontaneously.

One theory suggests absolute pitch evolved to "subserve speech, and that it may be readily acquired by the association of pitches with meaningful words very early in life, during the critical period in which infants acquire the main features of their native language"[5]. Tonal languages use this particular feature of language more than many western languages, including English, so do people with a tonal first language have a better sense of absolute pitch? It turns out that they do, and that it carries over to music. Deutsch et al. tested Chinese and US music students ages 17-34 for absolute pitch (defined as at least 85% correct answers identifying individual piano notes) gave results like these: "For those who had begun musical training between ages 8 and 9, roughly 42% of the Chinese students met the criterion whereas none of the US nontone language speakers did so."[6] It has been known a long time that most of the people with a good absolute pitch started their music training when very young, and this certainly seems to indicate if not a critical then at least a sensitive period for this type of development.

At this point you might ask yourself if you have some noticeable level of absolute pitch, so why not try it for yourself? You may not have the opportunity to listen to the same musical piece in different keys in order to compare them unless you or someone you know can play them, but if you have an instrument it is easy to pick it up and listen to individual notes. Play long notes and take your time. I would not be surprised if you thought the tones do not actually sound exactly the same. Some notes may sound a little "softer", others a little more "twangy". Putting it into words like this is like describing colour to someone totally colour-blind, and some people prefer instead to call the notes by colours (and no, those who do seldom agree which note is which colour). Also, some of the subtle differences you might hear could be because of the instrument (the different strings on the guitar will not sound the same), but these are usually easy to spot. The important thing is to take your time. Good luck!

References

[1] http://www.annalsnyas.org/cgi/content/full/1060/1/311, Sloboda, J.A., K.J. Wise & I. Peretz (2005). Quantifying tone deafness in the general population. Ann. N. Y. Acad. Sci. 1060: 255-261.

[2] The American Heritage Dictionary of the English Language, Fourth Edition ©2000, updated 2003, Houghton Mifflin Company

[3] http://www.reference.com/browse/columbia/absolpit, quoting The Columbia Electronic Encyclopedia Copyright © 2004, Columbia University Press

[4] http://www.highbeam.com, quoting The Concise Oxford Dictionary of Music, 1996

[5] http://psy.ucsd.edu/~ddeutsch/psychology/deutsch_research9.html, from the homepage of Diana Deutsch, Ph.D.

[6] http://www.aip.org/148th/deutsch.html, Deutsch et al. (2004). Perfect Pitch in Tonal Language Speakers Carries Over to Music, popular version of paper 3pMUb3, 148th ASA meeting, San Diego, CA

If you are interested in developing absolute pitch, this is the most pedagogical and well worked-out source I have come by so far:

Burge, D.L (1999) The Perfect Pitch Ear-training Supercourse. Information can be found at http://www.perfectpitch.com/