(1) A selection of tones in the octave, arranged in ascending or descending order, usually but not always using intervals of half- or whole-steps, and using the same notes in every successive octave. One tone is usually thought of as being the root, but it need not be the first note played. Most scales have 5, 6, 7 or 8 notes to the octave but any number from 2 to 12 is possible. (2) The same group of tones regarded abstractly as a 'pool' of available notes. In this sense, scale really means the same as chord. There is a maxim: 'Scales are chords and chords are scales. ' (3) A section of melody in the form of a scale.