Absolute and relative pitch

A note sounds on the piano, alone. One person says: "that's an A". Another says nothing about the note itself, but when a second note follows, says: "that one is a fifth higher". Both are hearing pitch, and they are doing two very different things.

A sound's pitch, absolute and relative

Before the words describe people, they describe sounds. The absolute pitch of a sound is its exact height, the one given by its number of vibrations per second. The relative pitch of a sound is what comes out of comparing it with another, which takes at least two sounds (Med 1996, ch. X).

An A at 440 vibrations per second has an absolute pitch. That it lies a fifth above the D before it is a relative fact: it describes the distance, and would stay true if both notes moved together.

Two kinds of ear

The same pair of words then names two abilities of the listener. Absolute pitch, or perfect pitch, is the ability to identify any musical sound and name it, with nothing to compare it to. Relative pitch is the ability to identify the differences of pitch between sounds (Med 1996, ch. XXXVIII).

The first names notes; the second names intervals. A person with relative pitch who is told the first note of a melody can work out all the others, because each step is a distance they recognise.

Why a tune survives a change of key

Sing a song you know starting on a higher note than usual. Every note changes, and the song is still the same song. Here is the opening of "Twinkle, Twinkle, Little Star" starting on C, and then starting on G:

Hear the passage

Hear the passage

Not a single note is shared between the two, and anyone recognises the tune. Med describes transposition in exactly these terms: it changes the absolute pitch of the sounds and keeps the intervals between them (Med 1996, ch. XXVII). What the ear holds on to is the relative part. That is why relative pitch, not absolute pitch, is the one music depends on: singing with others, playing by ear, recognising a progression, transposing a song to suit a voice.

Absolute pitch is rare

People with absolute pitch are few. Studies usually put it well under one person in a thousand in the general population, more common among musicians who began training very young and among speakers of tonal languages, where the pitch of a syllable changes its meaning. It is not a requirement for being a good musician, and many excellent musicians do not have it.

It can even get in the way. Someone who knows every A as 440 vibrations can find it uncomfortable to sing from a score while the band plays a semitone lower, or to hear a Baroque ensemble tuned below today's standard. The reference is a convention, and not every musician uses the same one.

Relative pitch can be trained

Relative pitch improves with practice, at any age. The usual path is the one this site's exercises follow:

1. Recognise intervals, first sung one after the other, then sounding together.
2. Hear each note of a scale by its place in it: the tonic, the fifth, the leading note that pulls up to the tonic.
3. Recognise chords by their quality, and progressions by the movement from one chord to the next.

A trick that helps with the first step is to link each interval to the opening of a song you already know, so that the song carries the distance for you.

What comes next

Relative pitch is built one distance at a time. The first distances to learn are the intervals, heard and named until they are as familiar as the tunes that carry them.