Inmusic, anaugmented sixth (Playⓘ) is aninterval produced bywidening amajor sixth by achromatic semitone.[1][4] 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 adissonant interval.[5]
| Inverse | diminished third |
|---|---|
| Name | |
| Other names | - |
| Abbreviation | A6[1] |
| Size | |
| Semitones | 10 |
| Interval class | 2 |
| Just interval | 125:72,[2] 225:128,[3] 7:4[citation needed], 59049:32768[citation needed] |
| Cents | |
| 12-Tone equal temperament | 1000 |
| Just intonation | 955, 977, 969, 1020 |
Itsinversion is thediminished third, and itsenharmonic equivalent is theminor seventh.
Inseptimal meantone temperament, it is specifically equivalent to theharmonic seventh (ajust interval of 7:4). In 12-toneequal temperament, the augmented sixth is equal to ten semitones and is adissonant interval.
The augmented sixth is relatively rare. Its most common occurrence is built on the loweredsubmediant of the prevailing key, in which position the interval assumes a natural tendency to resolve by expanding to anoctave built on thedominant tonal degree. In its most common and expected resolution, the lower note of the interval moves downwards by aminor 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.
As the augmented sixth is correctly named only in certain specific contexts, the notational distinction between it and the minor seventh is often ignored. Regardless of the truediatonic context, many writers are instead in favor of the more familiar minor seventh – especially in chord notation, in which chords containing it are always labeledseventh chords.
The augmented sixth interval in combination with certain other intervals forms the group of chords known collectively asaugmented sixth chords.
The just augmented sixth arises in the extended C major scale between A♭ and F♯.[6]Playⓘ
See also
editReferences
edit- ^abBenward & Saker (2003).Music: In Theory and Practice, Vol. I, p.54.ISBN 978-0-07-294262-0. Specific example of an A6 not given but general example of augmenting major intervals described.
- ^Haluska, Jan (2003).The Mathematical Theory of Tone Systems, p.xxvi.ISBN 0-8247-4714-3. Classic augmented sixth.
- ^Haluska, ibid. Augmented sixth.
- ^Hoffmann, F.A. (1881).Music: Its Theory & Practice, p.89-90. Thurgate & Sons. Digitized Aug 16, 2007. Archaic:superfluous orextreme sharp sixth.
- ^Benward & Saker (2003), p.92.
- ^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.
Further reading
edit- Hewitt, Michael (2000).The Tonal Phoenix: A Study of Tonal Progression Through the Prime Numbers Three, Five and Seven. Orpheus-Verlag.ISBN 978-3922626961