Chords
F# Half-diminished
F# · A · C · E
The half-diminished seventh — a diminished triad with a minor seventh. The ii of a minor key.
Also written F#ø · F#ø7 · F#-7b5 · F#h7 · F#h
F# Half-diminished
F# · A · C · E
Voicings on the piano
| Voicing | Notes | Play it on your instrument |
|---|---|---|
| Closed, root position | F#3 · A3 · C4 · E4 | |
| Open (drop 2) | C3 · F#3 · A3 · E4 | |
| Shell | F#3 · A3 · E4 | |
| Rootless | A3 · C4 · E4 · F#4 |
Tap a key or a fret to hear it.
Anatomy
F# Half-diminished (F#m7b5) contains the notes F# · A · C · E, each with a role measured as an interval from the root.
Read on: how triads are built · seventh chords
Inversions
An inversion of F# Half-diminished puts a chord tone other than F# in the bass; the name after the slash is that bass note.
Where it lives
The keys and the scales F# Half-diminished belongs to.
In which keys
F# Half-diminished is diatonic to 3 keys; the numeral is its degree and the label its harmonic function.
Scales that contain it
F# Half-diminished fits inside these scales, each built on F#.
- F# Minor BluesF# · A · B · C · C# · E
- F# LocrianF# · G · A · B · C · D · E
- F# Half-Whole DiminishedF# · G · A · A# · B# · C# · D# · E
- F# Locrian PentatonicF# · A · B · C · E
- F# Super Locrian PentatonicF# · A · Bb · C · E
- F# Locrian #2F# · G# · A · B · C · D · E
- F# Locrian 6F# · G · A · B · C · D# · E
- F# Dorian #4F# · G# · A · B# · C# · D# · E
Understanding the F# Half-diminished chord
Names and symbols
F#m7b5 is the chord symbol for F# Half-diminished; it is also written F#ø, F#ø7, F#-7b5, F#h7, F#h.
The half-diminished seventh is written m7♭5 on charts and ø7 (or just ø) in jazz notation; both name the same four notes. It is not the diminished seventh, °7, whose seventh is a semitone lower.
How it is built
On F# it is F# · A · C · E, stacking 1P · 3m · 5d · 7m. It is written m7♭5 or with the ø symbol, and both mean the same thing: a diminished triad softened by a minor rather than a diminished seventh.
How it is used
It is the ii of a minor ii–V–i, which makes it one of the most frequently played chords in jazz despite sounding exotic in isolation. It is also the chord built on the seventh degree of a major scale.
Unlike the fully diminished seventh it is not symmetrical, so it has a clear home and a clear direction: down a fifth, to the dominant.
Learn this properly
Chapter 10: Chords: Triads and SeventhsCommon questions
- What notes are in F#m7b5?
- F#m7b5 contains F# · A · C · E. Name any set of notes with the chord identifier.
- What is the difference between half-diminished and fully diminished?
- The seventh. Half-diminished uses a minor seventh; fully diminished lowers it again to a diminished seventh, which makes the chord symmetrical.
- Where is a half-diminished chord used?
- As the ii of a minor ii–V–i, and as the chord built on the seventh degree of a major scale.
- What notes are in the F# Half-diminished chord?
- The F# Half-diminished chord contains the notes F# · A · C · E: the root F# with the intervals 1P, 3m, 5d, 7m stacked above it. Play them together for the chord or one after another for an arpeggio. The lowest note is normally F#, but any chord tone can take the bass in an inversion.
- What intervals make up the F# Half-diminished chord?
- Measured from F#, the F# Half-diminished chord stacks the intervals 1P, 3m, 5d, 7m. The quality of the third and of the seventh, if there is one, is what gives the chord its character; the rest of the notes colour it. Every interval in the formula links to its own page, with its sound.