A Diminished Triads on Guitar: Every Inversion on Every String Set

A A diminished triad is A, C and E♭ (1 ♭3 ♭5). It has three arrangements, root position, first inversion and second inversion, and each can be played on four groups of three strings: all twelve shapes are below.

Keys

Triads — A°

Root position

8C shape
11A shape
1G shape
4E shape

The notes of A°

A diminished is two minor thirds stacked, so the outer notes are a diminished fifth (six frets) apart. Root position puts A at the bottom (A, C and E♭); first inversion puts C at the bottom (C, E♭ and A); second inversion puts E♭ at the bottom (E♭, A and C).

A° on every string set

On the low E, A and D strings: root position at frets 1–5, first inversion at frets 6–8 and second inversion at frets 0–11.

A° triad, root position, on the low E, A and D strings: A (root) on the low E string, fret 5; C on the A string, fret 3; E flat on the D string, fret 1.
Root position
A° triad, first inversion, on the low E, A and D strings: C on the low E string, fret 8; E flat on the A string, fret 6; A (root) on the D string, fret 7.
First inversion
A° triad, second inversion, on the low E, A and D strings: E flat on the low E string, fret 11; A (root) on the A string, fret 0; C on the D string, fret 10.
Second inversion

On the A, D and G strings: root position at frets 0–10, first inversion at frets 1–3 and second inversion at frets 5–7.

A° triad, root position, on the A, D and G strings: A (root) on the A string, fret 0; C on the D string, fret 10; E flat on the G string, fret 8.
Root position
A° triad, first inversion, on the A, D and G strings: C on the A string, fret 3; E flat on the D string, fret 1; A (root) on the G string, fret 2.
First inversion
A° triad, second inversion, on the A, D and G strings: E flat on the A string, fret 6; A (root) on the D string, fret 7; C on the G string, fret 5.
Second inversion

On the D, G and B strings: root position at frets 4–7, first inversion at frets 8–10 and second inversion at frets 1–2.

A° triad, root position, on the D, G and B strings: A (root) on the D string, fret 7; C on the G string, fret 5; E flat on the B string, fret 4.
Root position
A° triad, first inversion, on the D, G and B strings: C on the D string, fret 10; E flat on the G string, fret 8; A (root) on the B string, fret 10.
First inversion
A° triad, second inversion, on the D, G and B strings: E flat on the D string, fret 1; A (root) on the G string, fret 2; C on the B string, fret 1.
Second inversion

On the G, B and high e strings: root position at frets 11–14, first inversion at frets 4–5 and second inversion at frets 8–10.

A° triad, root position, on the G, B and high e strings: A (root) on the G string, fret 14; C on the B string, fret 13; E flat on the high e string, fret 11.
Root position
A° triad, first inversion, on the G, B and high e strings: C on the G string, fret 5; E flat on the B string, fret 4; A (root) on the high e string, fret 5.
First inversion
A° triad, second inversion, on the G, B and high e strings: E flat on the G string, fret 8; A (root) on the B string, fret 10; C on the high e string, fret 8.
Second inversion

Where the inversions sit in the CAGED shapes

The practice pad above shows A°'s triads inside each CAGED shape. Use the R, 2, 3 and V switches to see each arrangement:

  • Root position: C shape (fret 8), A shape (fret 11), G shape (fret 1) and E shape (fret 4).
  • First inversion: C shape (fret 8), A shape (fret 1) and E shape (fret 4).
  • Second inversion: C shape (fret 8), A shape (fret 1) and E shape (fret 5).

Where A° appears

A° belongs to 4 keys: vii° in B♭ major; ii° in G minor; ii° in G harmonic minor and vii° in B♭ harmonic minor.

None of them is one of the open-string guitar keys (C, G, D, A, E and their relative minors), so A° is more often met in piano-led songs, horn arrangements and with a capo.

Open strings and capo options for A°

One open string is part of A°: the A string (root). Because the root is among them, you can let it drone under any of the shapes.

The A° symmetry

A° is two minor thirds. Add a third minor third and you get a diminished seventh chord, which divides the octave into four: A°, C°, D♯° and F♯° all sit inside the same diminished seventh, so each shares two notes with A°.

A diminished triad is unstable: A°'s root is a semitone below B♭, and that's the chord it most wants to move to.

A° triad FAQs

What notes are in a A diminished triad?

A, C and E♭. The formula is 1 ♭3 ♭5.

What is the first inversion of A°?

C, E♭ and A, with C in the bass. On the G, B and high e strings it sits at fret 5, fret 4 and fret 5.

How many A° triad shapes are there?

Twelve to learn: root position and two inversions on each of the four three-string sets. They repeat twelve frets higher.

Learn more

How to use guitar triads explains inversions and how to use them in rhythm parts and solos, and triads on all string sets goes through each set in turn. The triad library has every chord.