Scale (music)

Scale (music)

In music, a scale is any sequence of musical notes in an ascending or descending order. Sometimes, scales contain both an ascending and a descending portion.

Often, especially in the context of the common practice period, part or all of a musical work including melody and/or harmony, is built using the notes of a single scale, which can be conveniently represented on a staff with a standard key signature.

The notes of a scale are ordered in pitch or pitch class. A measure of the distances (or intervals) between pairs of adjacent notes provides a method to classify scales. For instance, a major scale is defined by the interval pattern T-T-S-T-T-T-S, where T stands for whole tone, and S stands for semitone. Based on their interval patterns, scales are divided into categories including diatonic, chromatic, major, minor, and others.

A specific group of notes can be described, for instance, as a C-major scale, D-minor scale, etc.. This takes into account the selection of a special note, also known as the first degree (or tonic) of the scale. For example, C-major indicates a major scale in which C is the tonic.