Pitch

Full Description

Pitch is the perceptual quality of a sound that allows us to identify it as higher or lower in relation to other sounds. It is determined primarily by the frequency of the sound wave — the number of vibrations per second, measured in Hertz (Hz). A higher frequency produces a higher pitch; a lower frequency produces a lower pitch. The note A above middle C, the standard international tuning reference, vibrates at 440 Hz. In Western music, pitch is organised into twelve equally spaced semitones within each octave, a system known as equal temperament. This arrangement, standardised in the eighteenth century and refined through the work of musicians and theorists, allows instruments to play in any key without retuning. Earlier tuning systems — just intonation, meantone temperament, and others — prioritised purity of specific intervals at the expense of flexibility across keys. Notes are named using the letters A through G, with sharps and flats extending the system to all twelve chromatic pitches. The same twelve notes repeat across octaves, each octave doubling the frequency of the one below — A4 is 440 Hz, A5 is 880 Hz, A3 is 220 Hz. Absolute pitch (sometimes called perfect pitch) is the rare ability to identify or produce any given note without a reference tone. Relative pitch — the ability to identify intervals and notes in relation to a known reference — is far more common and is developed through ear training. Both are valuable skills, but relative pitch is the more musically practical of the two.