Major seventh
| Inverse | minor second |
|---|---|
| Name | |
| Other names | supermajor seventh |
| Abbreviation | M7 |
| Size | |
| Semitones | 11 |
| Interval class | 1 |
| Just interval | 15:8, 50:27 |
| Cents | |
| Equal temperament | 1100 |
| 24 equal temperament | 1150 |
| Just intonation | 1088, 1067 |
In classical music from Western culture, a seventh is a musical interval encompassing seven staff positions (see Interval number for more details), and the major seventh is one of two commonly occurring sevenths. It is qualified as major because it is the larger of the two. The major seventh spans eleven semitones, its smaller counterpart being the minor seventh, spanning ten semitones. For example, the interval from C to B is a major seventh, as the note B lies eleven semitones above C, and there are seven staff positions from C to B. Diminished and augmented sevenths span the same number of staff positions, but consist of a different number of semitones (nine and twelve).
The easiest way to locate and identify the major seventh is from the octave rather than the unison, and it is suggested that one sings the octave first. For example, the most commonly cited example of a melody featuring a major seventh is the tonic-octave-major seventh of the opening to "(Somewhere) Over the Rainbow". "Not many songwriters begin a melody with a major seventh interval; perhaps that's why there are few memorable examples." However, two songs provide exceptions to this generalisation: Cole Porter's "I love you" (1944) opens with a descending major seventh and Jesse Harris's "Don't Know Why",(made famous by Norah Jones in her 2002 debut album, Come Away with Me), starts with an ascending one.
The major seventh occurs most commonly built on the root of major triads, resulting in the chord type also known as major seventh chord or major-major seventh chord: including I7 and IV7 in major. "Major seven chords add jazziness to a musical passage. Alone, a major seventh interval can sound ugly."
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