Am7b5 Chord on Guitar
Am7b5 = A – C – D# – G (Root, Minor 3rd, Tritone, Minor 7th)
A half-diminished, written Am7b5, layers a flat seventh onto the plain diminished triad, softening its harshest edge while keeping real tension in the sound. At the fifth-fret barre it's a compact, four-note shape that's essential vocabulary for minor-key jazz playing even though it rarely appears in simpler guitar styles.
The notes are A, C, D#, G — root, minor third, diminished fifth, flat seventh. Half-diminished chords occupy a middle ground between plain minor sevenths and fully diminished sevenths: they're tenser than the former but less symmetrically unstable than the latter. Am7b5's most common real-world job is as the ii chord in a minor ii-V-i progression in G minor, leading through D7 into Gm — one of the most frequently used cadential patterns in jazz written in minor keys.
Fingerings
Barre (5th fret)
How to Practice It
Practice the full minor ii-V-i built on this chord — Am7b5 to D7 to Gm — since that's overwhelmingly how the chord is actually encountered in real playing rather than in isolation. Compare it against plain Adim (no seventh) and Adim7 (fully symmetrical) at the same position to hear how the three related diminished-family chords differ in exactly one note each.
Common Progressions
- Am7b5 – D7 – Gm (ii – V7 – i in G minor, the classic minor ii-V-i)
- Am7b5 – D7 – Gm7 (the same move with a fuller minor-seventh tonic)
- Bm7b5 – Am7b5 – Gm (a descending half-diminished passage)
- Am7b5 – D7alt – Gm (adding an altered dominant for extra tension)
FAQ
- What's the difference between Am7b5 and Adim7?
- Am7b5 has a flat seventh (G), while Adim7 has a diminished (double-flat) seventh (F#); the half-diminished chord is slightly less symmetrical and slightly less harsh than the fully diminished seventh.
- Why is Am7b5 called 'half-diminished'?
- It combines the diminished triad (root, minor third, flat fifth) with an ordinary flat seventh rather than a fully diminished seventh, so it carries some but not all of a fully diminished chord's tension — hence 'half.'
- Where does Am7b5 most commonly appear?
- As the ii chord in a minor ii-V-i progression in G minor, leading through D7 into a Gm resolution — one of the defining cadences of minor-key jazz harmony.
- Is Am7b5 the same thing as A° (A diminished) with a note added?
- It shares the same diminished triad base as plain Adim, with a flat seventh layered on top — so yes, in that sense it's Adim plus one added note, though musically the two serve quite different functions.
- Is Am7b5 difficult to finger?
- It's a moderately compact barre shape, generally comparable in demand to other four-note extended chords at the fifth fret, though the specific finger spread can feel unfamiliar until it's been practiced a few times.
- Why does Am7b5 sound less common in pop and rock guitar playing?
- Its tense, specifically jazz-harmony function doesn't have an obvious equivalent in most pop and rock progressions, which rarely use minor ii-V-i cadences, so the chord mostly stays confined to jazz, and jazz-influenced R&B and neo-soul writing.
- How does Am7b5 relate to Cm6?
- They share the same four notes — A, C, D#, G is identical in pitch content to C, D#, G, A spelled as a minor sixth chord — which mirrors the same shared-note relationship that links every minor sixth chord to a half-diminished chord built a major sixth above its root.
Am7b5 on other instruments: Am7b5 on Piano. Related: how chords are built, chord finder.