Ninth
| Inverse | minor seventh |
|---|---|
| Name | |
| Other names | compound second |
| Abbreviation | M9 |
| Size | |
| Semitones | 14 |
| Cents | |
| 12-Tone equal temperament | 1400.0 |
| Inverse | major seventh |
|---|---|
| Name | |
| Abbreviation | m9 |
| Size | |
| Semitones | 13 |
| Cents | |
| 12-Tone equal temperament | 1300.0 |
In music, a ninth is a compound interval consisting of an octave plus a second.
Like the second, the interval of a ninth is classified as a dissonance in common practice tonality. Since a ninth is an octave larger than a second, its sonority level is considered less dense.