In music from
Western culture
image:Da Vinci Vitruve Luc Viatour.jpg, Leonardo da Vinci's ''Vitruvian Man''. Based on the correlations of ideal Body proportions, human proportions with geometry described by the ancient Roman architect Vitruvius in Book III of his treatise '' ...
, a diminished octave () is an
interval produced by
narrowing a
perfect octave by a
chromatic semitone
In modern Western tonal music theory an augmented unison or augmented prime is the interval between two notes on the same staff position, or denoted by the same note letter, whose alterations cause them, in ordinary equal temperament, to be o ...
.
[Benward & Saker (2003). ''Music: In Theory and Practice, Vol. I'', p.54. . Specific example of an d8 not given but general example of perfect intervals described.] As such, the two notes are denoted by the same letter but have different
accidentals. For instance, the interval from C
4 to C
5 is a perfect octave, twelve semitones wide, and both the intervals from C
4 to C
5 and from C
4 to C
5 are diminished octaves, spanning eleven semitones. Being diminished, it is considered a
dissonant interval.
[Benward & Saker (2003), p.92.]
The diminished octave is
enharmonically equivalent to the
major seventh
In music from Western culture, a seventh is a musical interval encompassing seven staff positions (see Interval number for more details), and the major seventh is one of two commonly occurring sevenths. It is qualified as ''major'' because it is ...
.
References
Diminished intervals
Octaves
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