In classical music from Western culture, a diminished sixth () is an interval produced by narrowing a minor sixth by a chromatic semitone.Benward & Saker (2003). Music: In Theory and Practice, Vol. I, p.54. . Specific example of an d6 not given but general example of minor intervals described.Hoffmann, F.A. (1881). Music: Its Theory & Practice, p.89-90. Thurgate & Sons. Digitized Aug 16, 2007. For example, the interval from A to F is a minor sixth, eight semitones wide, and both the intervals from A to F, and from A to F are diminished sixths, spanning seven semitones.
Being diminished, it is considered a dissonant interval,Benward & Saker (2003), p.92. despite being equivalent to an interval known for its consonance. Its inversion is the augmented third, and its enharmonic equivalent is the perfect fifth.
"Wolf fifth"
A severely dissonant diminished sixth is observed when a fixed-pitch instrument limited to twelve notes per octave is tuned using Pythagorean tuning or a meantone temperament with a fifth flatter than 700 cents. Typically, this is the interval between G and E. Since this interval was considered to "howl like a wolf" (because of the beating), and since it sounded like a badly out-of-tune fifth, this interval is called the "wolf" fifth. A justly tuned fifth is the most consonant interval after the perfect unison and the perfect octave.
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