The musical interval of a Major seventh the first note (the root or tonic) and the seventh, the leading tone, in a major scale. It is the inversion of the minor second.
It can be produced by starting on a high note and playing the seventh below or by starting on a low note and playing the seventh above.
A Major seventh in just intonation corresponds to a pitch ratio of 15:8 or 1:1.875, or various other ratios, while in an equal tempered tuning it is a ratio of 1:211/12 (approximately 1.887), or 1100 cents, 11.731 centss sharp of 15:8.
The Major seventh is considered the second most dissonant interval after its inversion the minor second.