Augmented second
Inverse | diminished seventh |
|---|---|
| Name | |
| Other names | - |
| Abbreviation | A2[1] |
| Size | |
| Semitones | 3 |
| Interval class | 3 |
| Just interval | 75:64,[2] 125:108, 15:13, 19:16, 19683:16384 |
| Cents | |
| 12-Tone equal temperament | 300 |
| Just intonation | 275, 253, 247.7, 298, 318 |
In
For instance, the interval from C to D is a major second, two semitones wide, and the interval from C to D♯ is an augmented second, spanning three semitones.Usage
Augmented seconds occur in many scales, most importantly the
cadence observed in major keys, where the V chord is "dominant" (that is, contains a major triad plus a minor seventh
).
Tuning
An augmented second is
enharmonically equivalent to a minor third (ⓘ) in equal temperament, but is not the same interval in other meantone tunings. In any tuning close to quarter-comma meantone it will be close to the 7:6 ratio of the septimal minor third
.
The 75:64 just augmented second arises in the justly tuned C harmonic minor scale between A♭ and B.[4] ⓘ
References
- ^ ISBN 978-0-07-294262-0. Specific example of an A2 not given but general example of major intervals described.
- ISBN 0-8247-4714-3. Classic augmented second.
- ^ Hoffmann, F.A. (1881). Music: Its Theory & Practice, p.89-90. Thurgate & Sons. Digitized Aug 16, 2007. Archaically: redundant or extreme sharp second.
- ^ Paul, Oscar (1885). A manual of harmony for use in music-schools and seminaries and for self-instruction, p.165. Theodore Baker, trans. G. Schirmer.