major scale, in music, stepped arrangement of notes following the classical Greek Ionian mode (though mistaken nomenclature in the 16th century has since caused it to be referred to as the Lydian mode). In a major scale the intervals between successive notes after the first are tone, tone, semitone, tone, tone, tone, semitone. Thus, the major scale of D is D–E–F♯–G–A–B–c♯–d, and the same notes descending.