Am7♭5 chord on guitar
The Am7♭5 chord, or A half-diminished, stacks 4 notes on A: A, C, E♭ and G. Musicians write its formula 1 ♭3 ♭5 ♭7.
Notes and intervals of Am7♭5
Each note of Am7♭5 has a job. Counted from the root, you get root (A), minor 3rd (C), diminished 5th (E♭) and minor 7th (G). Change one of these intervals and you get a different chord, which is why the formula 1 ♭3 ♭5 ♭7 is worth memorising rather than the shape alone.
| Degree | Interval | Note |
|---|---|---|
| 1 | root | A |
| ♭3 | minor 3rd | C |
| ♭5 | diminished 5th | E♭ |
| ♭7 | minor 7th | G |
How to play Am7♭5 on guitar
Start with the first diagram: x 0 1 0 1 x, read from the 6th string (low E) to the 1st string (high E). Your lowest note is A. The next positions give the same notes in a different order, which is useful when you want Am7♭5 to sit closer to the surrounding chords.
Let the open strings ring: strum slowly once and check that every note sounds clean before you speed up.
Which keys use Am7♭5?
You find Am7♭5 as a diatonic chord in B flat major (viiø7). The most common case is B flat major, where it plays the role of viiø7.
Scales to play over Am7♭5
These scales share every note of Am7♭5: A blues scale and A Locrian mode. A blues scale is the safest choice; the others add more colour.
About half-diminished chords
A diminished triad plus a minor seventh: 1 ♭3 ♭5 ♭7. Called half-diminished (ø), it is dark and unsettled but softer than a full diminished seventh, because its seventh is minor. It sounds like a question, a sigh that wants to move on. For example Bm7♭5: B D F A.
Its main home is the minor ii-V-i: iiø7 V7 i (for example Bm7♭5 E7 Am). In a major key it sits on viiø7. Jazz, bossa nova and neo-soul use it constantly, and it can also stand in for ivm6 in a minor key, since both chords share the same notes (for example Bm7♭5 and Dm6).
Two movable shapes cover most needs: root on the 5th string (for example Bm7♭5 x2323x) and root on the 6th string with the 5th string muted (for example Bm7♭5 7x776x). Learn each one together with the 7 chord and the minor chord that follow it in a minor ii-V-i, in the same area of the neck.
m7♭5 is not dim7: dim7 has a diminished seventh (A♭ in Bdim7), m7♭5 a minor seventh (A in Bm7♭5). It is not m6 either, although the two share notes: the bass decides. And remember that m7♭5, m7(♭5), -7♭5 and ø7 are all names for the same chord.
Frequently asked questions
What notes are in the Am7♭5 chord?
Am7♭5 (A half-diminished) contains A, C, E♭ and G. In intervals: root (A), minor 3rd (C), diminished 5th (E♭) and minor 7th (G).
How do you play Am7♭5 on guitar?
The easiest shape is x 0 1 0 1 x, from the low E string to the high E string. This page shows 3 positions with finger numbers.
What scale goes with Am7♭5?
A blues scale fits Am7♭5 best. Other scales that contain all its notes: A Locrian mode.
What key is Am7♭5 in?
Am7♭5 belongs to B flat major (viiø7). In B flat major it is the viiø7 chord.
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