A#dim7 (Bbdim7) Guitar Chord
A#dim7 (A# diminished seventh) is a four-note chord made from A#, C#, E and G. A diminished seventh is minor thirds stacked all the way up, so it is symmetrical: the same shape moved up three frets plays the same notes. It makes a tense passing chord that leads up a half step.
A#dim7 A# diminished seventh
Open position1 / 5
Notes
- A#1
- C#b3
- Eb5
- Gbb7
Built from the root A#, the minor third C#, the flat fifth E and the diminished seventh G.
Also written Bbdim7: Bb Db Fb Abb
How to play A#dim7
Frets from low E to high E; x means don't play that string.
Easiest shape to start with: Open position (x12020). It has 2 open strings, nothing above fret 2 and 1 muted string.
Keys with A#dim7
Every note of A#dim7 is in these keys. The numeral is its place in the key.
Minor keys
- vii°7 in B harmonic minor