Tools / Chords / C augmented major 7th

C augmented major 7th chord on bass (CaugMaj7)

Also written CaugMaj7, CaugM7 or C+M7

C augmented major 7th is built from C, E, G♯ and B. The default voicing requires a wide stretch between the index and pinky fingers.

CaugM7/G♯ inversion4-3-2-4

Positions on the neck1 of 2

How it’s built

C1Root

E3Major 3rd

G♯♯5Augmented 5th

B7Major 7th

Formula 1, 3, ♯5, 7

Positions on the neck1 of 2

Inversions

The same three notes, with a different one in the bass.

Root positionC–E–G♯–BCaugMaj7Bass C

First inversionE–G♯–B–CCaugMaj7/EBass E

Second inversionG♯–B–C–ECaugMaj7/G♯Bass G♯

Third inversionB–C–E–G♯CaugMaj7/BBass B

Why it sounds like that

C augmented major 7th is built as 1–3–♯5–7, with major thirds between C and E, and E and G♯. The raised fifth G♯ gives the chord its augmented tension, while the major seventh B adds brightness. Compare C major 7th, which has a perfect fifth G.

What goes wrong with C augmented major 7th?

Letting the pinky collapse onto the 1st string, causing a buzz.
Allowing the index finger to touch the 3rd string, deadening the E.

When to use it

C augmented major 7th works as a passing chord between C major and E major, or as a substitute for C major 7th in jazz. Its bright, tense sound suits fusion and modern jazz.

Changing to and from C augmented major 7th

Sliding the shape down one fret to the 1st fret gives B augmented major 7th.
Sliding the shape up one fret to the 3rd fret gives C♯ augmented major 7th.

Which voicing to use

The G♯ inversion places the augmented fifth in the bass, creating a restless, upward-pulling sound. The B inversion puts the major seventh in the bass, which darkens the chord and works well for descending bass lines.

How do you play a C augmented major 7th chord on bass?

CaugM7/G♯ inversion

Intermediate● On the diagram

C augmented major 7th is played at the 2nd fret as 4 3 2 4: ring finger on the E string at fret 4, middle finger on the A string at fret 3, index finger on the D string at fret 2 and pinky finger on the G string at fret 4.

Tip — The pinky must reach the 4th fret on the 1st string while the index holds the 2nd fret on the 2nd string, creating a wide stretch.

String-by-string breakdown

String	Fret	Finger	Note
4 (E)	4	3	G♯ (♯5)
3 (A)	3	2	C (1)
2 (D)	2	1	E (3)
1 (G)	4	4	B (7)

CaugM7/B inversion

Intermediate

C augmented major 7th is played at the 5th fret as 7 7 6 5: ring finger on the E string at fret 7, pinky finger on the A string at fret 7, middle finger on the D string at fret 6 and index finger on the G string at fret 5.

String-by-string breakdown

String	Fret	Finger	Note
4 (E)	7	3	B (7)
3 (A)	7	4	E (3)
2 (D)	6	2	G♯ (♯5)
1 (G)	5	1	C (1)

Common questions

How is C augmented major 7th written?

C augmented major 7th is written C+M7, M7#5, maj+7, or CaugM7. It is also called augmented major seventh or major seventh sharp five.

What is the difference between C augmented major 7th and C augmented?

C augmented major 7th adds the major seventh B to the augmented triad C–E–G♯. C augmented lacks the seventh, so it has less harmonic pull.

Why does C augmented major 7th sound unstable?

The augmented fifth G♯ creates a symmetrical division of the octave, leaving no clear tonal centre. The major seventh B adds further tension, making the chord want to resolve.

String

Fret

Finger

Note

4 (E)

G♯ (♯5)

3 (A)

C (1)

2 (D)

E (3)

1 (G)

B (7)

String

Fret

Finger

Note

4 (E)

B (7)

3 (A)

E (3)

2 (D)

G♯ (♯5)

1 (G)

C (1)