A major second, whole tone, or whole step is one of three commonly occurring musical intervals that span two diatonic scale degrees; the others being the minor second and the augmented second, which is one semitone larger. The major second is abbreviated as M2 and its inversion is the minor seventh. It occurs naturally between the 1st and 2nd degrees of a major scale, as the tonic rising melodically to the supertonic (the familiar Do-Re sung in moveable-do solfege).
In just intonation, the major second can correspond to at least two different frequency ratios: 9/8 (the major tone), and 10/9 (the minor tone), which differ by the syntonic comma. In meantone temperament and equal temperament these two intervals are approximated by the same interval.
The major second is considered one of the more dissonant intervals of the diatonic scale. It is a characteristic of Arabic music, Turkish music and music of the Balkans.
