Augmented sixth
| Inverse | diminished third |
|---|---|
| Name | |
| Other names | - |
| Abbreviation | A6 |
| Size | |
| Semitones | 10 |
| Interval class | 2 |
| Just interval | 125:72, 225:128, 7:4 |
| Cents | |
| Equal temperament | 1000 |
| 24 equal temperament | 1000 |
| Just intonation | 955, 977, 969 |
In classical music from Western culture, an augmented sixth (
Play ) is an interval produced by widening a major sixth by a chromatic semitone. For instance, the interval from C to A is a major sixth, nine semitones wide, and both the intervals from C♭ to A, and from C to A♯ are augmented sixths, spanning ten semitones. Being augmented, it is considered a dissonant interval.
Its inversion is the diminished third, and its enharmonic equivalent is the minor seventh.
In septimal meantone temperament, it is specifically equivalent to the harmonic seventh (a just interval of 7/4). In the tuning system known as equal temperament the augmented sixth is equal to ten semitones and is a dissonant interval.
The augmented sixth is relatively rare. Its most common occurrence is built on the lowered submediant of the prevailing key, in which position the interval assumes a natural tendency to resolve by expanding to an octave built on the dominant tonal degree. In its most common and expected resolution, the lower note of the interval moves downwards by a minor second to the dominant while the upper note, being chromatically inflected, is heard as the leading note of the dominant key, rising naturally by a minor second. It is the strong tendency to resolve in this way that properly identifies this interval as being an augmented sixth rather than its more common enharmonic equivalent: the minor seventh, which has a tendency to resolve inwardly.
...
Wikipedia