A# Diminished 7th Guitar Chord
Voicing Positions (6)
Interval Colors
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A# Diminished 7th Chord
The A# Diminished 7th chord is built from the intervals: Root, Minor 3rd, Tritone, and Major 6th. It contains the notes A#, C#, E, and G. The added seventh gives this chord a richer, more complex sound.
What A# Diminished 7th Is
The A# Diminished 7th is a diminished triad — a stack of two minor thirds. Both intervals are minor, which makes the chord sound deeply unstable. Diminished triads function as the seventh degree of major scales and the second degree of minor scales; they almost never act as a final resting point but instead pull strongly toward whatever chord lives a half-step above their root.
How A# Diminished 7th Sounds
A A# Diminished 7th sounds tense and incomplete. The diminished fifth is one of the most unstable intervals in tonal music, and stacking two minor thirds doubles down on the unease. In a piece of music a A# Diminished 7th almost always wants to move somewhere — most often a half-step up or down to the nearest stable chord.
How To Use A# Diminished 7th In A Progression
Diminished triads and seventh chords most often function as passing harmony. They lead from one stable chord to another, usually by half-step. In jazz, fully diminished seventh chords are also used as substitutes for dominant seventh chords with a flat ninth — they share three notes and resolve to the same place.
Playing A# Diminished 7th On Guitar
On guitar, the most common voicings of A# Diminished 7th use the open position when possible (which is why guitarists tend to favour keys like E, A, D, G, and C) and movable barre or half-barre shapes everywhere else. The voicing diagrams above show several practical positions across the neck — the open or low-fret voicings will sound brightest, while the higher voicings will have a thinner, more focused tone. Always experiment with which fingering serves the line you are playing.
Related Chords
Same quality (Diminished 7th)
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