Diminished triad
In music theory, a diminished triad (also known as the minor flatted fifth) is a triad consisting of two minor thirds above the root.[3] It is a minor triad with a lowered (flattened) fifth. When using chord symbols, it may be indicated by the symbols "dim", "o", "m♭5", or "MI(♭5)".[4] However, in most popular-music chord books, the symbol "dim" and "o" represents a diminished seventh chord (a four-tone chord), which in some modern jazz books and music theory books is represented by the "dim7" or "o7" symbols.
"Diminished chord" redirects here. For the seventh chord, see Diminished seventh chord.
For example, the diminished triad built on B, written as Bo, has pitches B-D-F:
The chord can be represented by the integer notation {0, 3, 6}.
In the common practice period, the diminished triad is considered dissonant because of the diminished fifth (or tritone).
In popular music[edit]
Walter Everett writes that "In rock and pop music, the diminished triad nearly always appears on the second scale degree, forming a generally maudlin and dejected iio with its members, 2–4–♭6."[9] Songs that feature iio include Santo & Johnny's "Sleep Walk", Jay and the Americans' "Cara Mia", and the Hollies' "The Air That I Breathe".[9] Not so rare but rare enough so as to imply knowledge of and conscious avoidance on the part of rock musicians, examples of its use include Oasis' "Don't Look Back in Anger", David Bowie's "Space Oddity", and two in Daryl Hall's "Everytime You Go Away".[10]
The viio in major keys is relatively less common than the iio, but still does happen. It is almost always used to tonicize the relative minor, in progressions such as viio–V7/vi–vi, which resembles iio–V7–i in the relative minor.
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