Neutral second
| Inverse | neutral seventh |
|---|---|
| Name | |
| Abbreviation | n2 |
| Size | |
| Semitones | ~1½ |
| Interval class | ~1½ |
| Just interval | 11:10 or 12:11 |
| Cents | |
| Equal temperament | 100 or 200 |
| 24 equal temperament | 150 |
| Just intonation | 165 or 151 |
| Inverse | neutral second |
|---|---|
| Name | |
| Other names | - |
| Abbreviation | n7 |
| Size | |
| Semitones | ~10½ |
| Interval class | ~1½ |
| Just interval | 11:6, 64:35, or 24:13 |
| Cents | |
| Equal temperament | 1000 or 1100 |
| 24 equal temperament | 1050 |
| Just intonation | 1049, 1045, or 1061 |
In music theory, a neutral interval is an interval that is neither a major nor minor, but instead in between. For example, in equal temperament, a major third is 400 cents, a minor third is 300 cents, and a neutral third is 350 cents. A neutral interval inverts to a neutral interval. For example, the inverse of a neutral third is a neutral sixth.
Roughly, neutral intervals are a quarter tone sharp from minor intervals and a quarter tone flat from major intervals. In just intonation, as well as in tunings such as 31-ET, 41-ET, or 72-ET, which more closely approximate just intonation, the intervals are closer together.
A neutral second or medium second is an interval wider than a minor second and narrower than a major second. Three distinct intervals may be termed neutral seconds:
The equal-tempered neutral second may be found in the quarter tone scale and in some traditional Arab music (see also Arab tone system). Because neutral seconds are essentially a semitone (minor second) plus a quarter-tone, they may be considered three-quarter tones.
Approximations to the 12:11 and 11:10 neutral seconds can be found in a number of equally tempered tuning systems. 11:10 is very closely matched by 22-ET, whereas 12:11 is matched by 24-ET, 31-ET and 41-ET. 72-ET matches both intervals closely and is also the smallest widely used equal temperament that uniquely matches both intervals. Tuning systems that temper out the comma of 121:120 do not distinguish between the two intervals. 17-ET has a neutral second between 12:11 and 13:12, and a neutral third between 16:13 and 11:9.
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Wikipedia