A
heptatonic scale is a musical
scale that has seven
pitches per
octave. Examples include the
major scale (or
minor scale), (e.g., in
C major: C D E F G A B C—and in the
relative minor,
A minor: A B C D E F G); the
melodic minor scale, C D E F G A B C ascending, C B A G F E D C descending; the
harmonic minor scale, C D E F G A B C; and a scale variously known as the Roman
Byzantine, and
Hungarian, scale, C D E F G A B C. Indian Classical theory postulates seventy-two seven-tone scale types, whereas others postulate twelve or ten (depending on the theorist) seven-tone scale types collectively called
thaat.