User:Sonia/Diminished seventh
 | This article does not have any sources. (December 2009) |
| Inverse | augmented second | |
|---|---|---|
| Name | ||
| Other names | - | |
| Abbreviation | d7 | |
| Size | ||
| Semitones | 9 | |
In music theory, a diminished seventh (
play (help·info)) is an interval encompassing nine semitones. It spans seven scale degrees and contains nine half steps, being one semitone smaller than a minor seventh and enharmonically equivalent to a major sixth. Its inversion is the augmented second.
The diminished seventh is used quite readily in the minor key, where it is present in the harmonic minor scale between the seventh scale step and the sixth scale step in the octave above.
In an equal tempered tuning, a diminished seventh is equal to nine semitones, a ratio of 29/12:1 (approximately 1.682), or 900 cents. There is no standard just tuning of this interval, but one possibility, assuming the flat submediant is a perfect (5:4) major third below the octave, and the leading tone to be 15:16, would lead to an interval of 128:75, about 925 cents; another interval is 216:125, which is three minor thirds.
See also change