pitch (music)

In music, pitch is the perception of the frequency of a note. For example, the A above middle C is nowadays set at 440 Hz (often written as "A = 440 Hz", and known as concert pitch), although this has not always been the case (see #Historical pitch standards). Pitch is often cited as one of the fundamental aspects of music.

Pitch is something perceived by the human ear, as opposed to frequency, the physical measurement of vibration. The note A above middle C played on any instrument is perceived to be of the same pitch as a pure tone of 440Hz, but does not necessarily contain that frequency or only that frequency. Furthermore, a slight change in frequency need not lead to a perceived change in pitch, but a change in pitch implies a change in frequency. In fact, the just noticeable difference (the threshold at which a change in pitch is perceived) is about five cents, but varies over the range of hearing and is more precise when the two pitches are played simultaneously. Like other human stimuli, the perception of pitch also can be explained by the Weber-Fechner Law.

Note (Tone) - the abstract concept of note refers both to a unit of fixed pitch which has been given a name, and also to the graphic representation of that pitch in a notation system, and sometimes its duration.
Pitch (music) - the perceived frequency of a note or sound. See also pure tone.