Diminished fourth

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diminished fourth

Inverse	augmented fifth
Name
Other names	-
Abbreviation	d4
Size
Semitones	4
Interval class	4
Just interval	32:25
Cents
Equal temperament	400
Just intonation	427

In music, a diminished fourth is an interval that spans four diatonic scale degrees, and is narrower than a perfect fourth by a chromatic semitone.

A diminished fourth is enharmonically equivalent to a major third; that is, it spans the same number of semitones, and they are physically the same pitch in twelve-tone equal temperament. For example, B–D♯ is a major third; but if the same pitches are spelled B and E♭, the interval is instead a diminished fourth. B–E^b occurs in the C harmonic minor scale.

v • d • e Intervals Perfect unison (0) · fourth (5) · fifth (7) · octave (12) Major second (2) · third (4) · sixth (9) · seventh (11) Minor second (1) · third (3) · sixth (8) · seventh (10) Augmented unison (1) · second (3) · third (5) · fourth (6) · fifth (8) · sixth (10) · seventh (12) Diminished second (0) · third (2) · fourth (4) · fifth (6) · sixth (7) · seventh (9) · octave (11) Septimal major (supermajor) second (2½) · third (4½) · sixth (9½) · seventh (11½) Neutral second (1½) · third (3½) · sixth (8½) · seventh (10½) Septimal minor (subminor) second (½) · third (2½) · sixth (7½) · seventh (9½) Semitones are given in brackets. Fractional semitones are approximate.