What A♯dim7 is built from
Counting up in semitones from A♯:
| Note | Interval | Semitones from root |
|---|---|---|
| A♯ | root | 0 |
| C♯ | minor third | 3 |
| E | diminished fifth | 6 |
| G | diminished seventh | 9 |
Move all four of those the same distance and you get the same chord on another root — that is what the diminished seventh formula 0 – 3 – 6 – 9 means.
How to play A♯dim7
Leave the low E string out. Nothing is higher than fret 3, so it sits in first position.
All four strings are played. The G and E strings ring open. Nothing is higher than fret 1, so it sits in first position.
Play A♯, C♯, E and G together. That is two white keys and two black.
Numbers in the grids are frets. Where a number is printed beside a grid, that is the fret the top row stands for; otherwise the thick bar at the top is the nut. A circle above a string means play it open, a cross means leave it out.
Guitar, string by string
| Guitar string | Stopped at | Sounds |
|---|---|---|
| low E | not played | — |
| A | fret 1 | A♯ |
| D | fret 2 | E |
| G | fret 3 | A♯ |
| B | fret 2 | C♯ |
| top E | fret 3 | G |
Ukulele, string by string
| Ukulele string | Stopped at | Sounds |
|---|---|---|
| G | open | G |
| C | fret 1 | C♯ |
| E | open | E |
| A | fret 1 | A♯ |
A♯dim7 on the stave
The same four notes written on a treble stave, spelled the way a diminished seventh is spelled — one letter for every other step, with whichever accidental reaches the pitch. That is why it reads A♯, C♯, E and G, and not the same sounds written some other way.
Which keys A♯dim7 belongs to
No major scale contains all four of these notes. It does sit inside the harmonic minor scale, which is where it is usually met:
- B harmonic minor, on degree vii°7
Other chords on A♯
Same root, different notes above it.
Chords straight off a recording
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