In
music theory
Music theory is the study of the practices and possibilities of music. ''The Oxford Companion to Music'' describes three interrelated uses of the term "music theory". The first is the "rudiments", that are needed to understand music notation (ke ...
, the half-diminished seventh chord (also known as a half-diminished chord or a minor seventh flat five chord) is a
seventh chord composed of a
root note
In music theory, the concept of root is the idea that a chord can be represented and named by one of its notes. It is linked to harmonic thinking—the idea that vertical aggregates of notes can form a single unit, a chord. It is in this sense ...
, together with a
minor third, a
diminished fifth
Diminished may refer to:
*Diminution
In Western music and music theory, diminution (from Medieval Latin ''diminutio'', alteration of Latin ''deminutio'', decrease) has four distinct meanings. Diminution may be a form of embellishment in which ...
, and a
minor seventh (1, 3, 5, 7). For example, the half-diminished seventh chord built on C, commonly
written as Cm7(♭5), or C
7, has pitches C–E–G–B:
:
It can be represented by the
integer notation
In music, a pitch class (p.c. or pc) is a set of all pitches that are a whole number of octaves apart; for example, the pitch class C consists of the Cs in all octaves. "The pitch class C stands for all possible Cs, in whatever octave positio ...
.
The half-diminished seventh chord exists in
root position and in three inversions. Note that the first inversion shares identity with a chord on the minor sixth:
In
diatonic
Diatonic and chromatic are terms in music theory that are most often used to characterize Scale (music), scales, and are also applied to musical instruments, Interval (music), intervals, Chord (music), chords, Musical note, notes, musical sty ...
harmony
In music, harmony is the process by which individual sounds are joined together or composed into whole units or compositions. Often, the term harmony refers to simultaneously occurring frequencies, pitches ( tones, notes), or chords. However ...
, the half-diminished seventh chord occurs naturally on the seventh
scale degree
In music theory, the scale degree is the position of a particular note on a scale relative to the tonic, the first and main note of the scale from which each octave is assumed to begin. Degrees are useful for indicating the size of intervals and ...
of any