In music, a scale is an ascending or descending series of notes or pitcheses, as opposed to a series of intervalss, which is a musical mode. Each note in a scale is referred to as a scale degree. Though the scales from musical traditions around the world are often quite different, the pitches of the notes in any given scale are usually related by a mathematical rule. Scales are theoretical constructs which may be used to control a composition, but much music is written without any scale in mind. Scales may be described as tonal, modal, diatonic, derived or synthetic, and by the number of tones included.

Table of contents
1 Scales in Western music
2 Scale degrees
3 Non-Western scales
4 Microtonal scales
5 Jazz and blues
6 Chords
7 Psychoacoustical scales

Scales in Western music

Scales in traditional Western music consist of seven notes, made up of a root note and six other scale degrees whose pitches lie between the root and its first octave. Notes in the scale are separated by whole and half step intervalss of tones and semitones.

There are a number of different types of scales used commonly in Western music, including:

Synthetic scales:

Scale degrees

A scale degree is a numeric position of a note within a scale ordered by increasing pitch. The simplest system is to name each degree after its numerical position in the scale, for example: the first, the fourth. Because
intervals are inclusive, a fifth describes a note which is four notes after the tonic.

Major scales have seven notes which are named, in order: tonic, supertonic, mediant, subdominant, dominant, submediant, leading-tone (or leading-note). Also commonly used is the "movable do" solfege naming convention in which each scale degree is given a syllable. In the major scale, the solfege syllables are: Do, Re, Mi, Fa, So, La, Ti, Do.

Non-Western scales

In traditional Western music, scale degrees are separated by tones or semitones. However, many other musical traditions employ scales that include other intervals. The music of India demonstrates some excellent examples, as some ragas employ scale intervals smaller than a semitone. See gamelan also.

Microtonal scales

The term microtonal music usually refers to music with roots in traditional Western music that employs non-standard scales or scale intervals. The composer Harry Partch made custom musical instruments to play compositions that employed a 43-note scale system, and the American jazz vibraphonist Emil Richards experimented with such scales in his 'Microtonal Blues Band' in the 1970s.

Jazz and blues

Through the introduction of blue notes, jazz and blues employ scale intervals smaller than a semitone. See also: Jazz scales.

Chords

The notes in a
chord are usually a subset of a particular scale, in the common practice period being built upward by thirds from a particular scale degree. Thus in a C major scale: CDEFGAB, a chord built on C is the notes CEG.

Psychoacoustical scales

The bark scale and the mel scale are two psychoacoustical scales.