Eleventh (interval)
Main interval nameperfect eleventh
Inverseperfect fifth
Other namesCompound fourth
AbbreviationP11
Semitones17
Interval class1
Just interval8:3
Cents equal temperament1700.0
Cents just intonation1698.0
Eleventh (interval)
Main interval nameaugmented eleventh
Inversediminished fifth
AbbreviationA11
Semitones18
Interval class6
Just interval45:16
Cents equal temperament1800.0
Cents just intonation1790.2

In music theory, an eleventh is a compound interval consisting of an octave plus a fourth. A perfect eleventh spans 17 and the augmented eleventh 18 semitones, or 10 steps in a diatonic scale. For instance, the interval between C4 and F5 (in scientific pitch notation) is a perfect eleventh.

Since there are only seven degrees in a diatonic scale, the eleventh degree is the same as the subdominant (IV).[1]

An eleventh chord is the stacking of five thirds in the span of an eleventh. In common practice tonality, it usually had subdominant function as minor eleventh chord on the second degree (supertonic) of the major scale.

The quarter tone scale offers an alternative eleventh of 1650 cents, which is very close to the just interval 11:4, the undecimal eleventh (1651.3 cents).

See also

References

  1. ^ Benward, Bruce & Saker, Marilyn (2003). Music: In Theory and Practice, Vol. I. McGraw-Hill Education. ISBN 978-0-07-294262-0.