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B augmented major 7th chord on bass (BaugMaj7)
Also called or written BaugMaj7, BaugM7, B+M7, BM7#5, Bmaj+7, B augmented major seventh or B major seventh sharp five
B augmented major 7th is built from B, D♯, F♯♯ and A♯. The default voicing sits low on the neck, requiring precise finger placement in a tight cluster.
How it is built
Formula 1, 3, ♯5, 7
How do you play a B augmented major 7th chord on bass?
B augmented major 7th is played at the 1st fret as 3 2 1 3: ring finger on the E string at fret 3, middle finger on the A string at fret 2, index finger on the D string at fret 1 and pinky finger on the G string at fret 3.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 3 | 3 | F♯♯ (♯5) |
| 3 (A) | 2 | 2 | B (1) |
| 2 (D) | 1 | 1 | D♯ (3) |
| 1 (G) | 3 | 4 | A♯ (7) |
AdvancedThe cluster of frets 1–3 forces the fingers into a cramped position, making clean fretting difficult.
BaugM7/F♯♯ inversion · fret 13
B augmented major 7th is played at the 13th fret as 15 14 13 15: ring finger on the E string at fret 15, middle finger on the A string at fret 14, index finger on the D string at fret 13 and pinky finger on the G string at fret 15.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 15 | 3 | F♯♯ (♯5) |
| 3 (A) | 14 | 2 | B (1) |
| 2 (D) | 13 | 1 | D♯ (3) |
| 1 (G) | 15 | 4 | A♯ (7) |
BaugM7/A♯ inversion
B augmented major 7th is played at the 4th fret as 6 6 5 4: ring finger on the E string at fret 6, pinky finger on the A string at fret 6, middle finger on the D string at fret 5 and index finger on the G string at fret 4.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 6 | 3 | A♯ (7) |
| 3 (A) | 6 | 4 | D♯ (3) |
| 2 (D) | 5 | 2 | F♯♯ (♯5) |
| 1 (G) | 4 | 1 | B (1) |
Why it sounds like that
B augmented major 7th is built as 1–3–♯5–7, with major thirds between B and D♯, and D♯ and F♯♯. The double-sharped fifth F♯♯ (enharmonically G) gives the chord its augmented colour, while the major seventh A♯ adds brightness. Compare B major 7th, which has a perfect fifth F♯.
What goes wrong with B augmented major 7th?
- Letting the index finger mute the 3rd string while fretting the 2nd.
- Pressing too hard with the pinky, causing the 1st string to go sharp.
When to use it
B augmented major 7th works as a passing chord between B major and E♭ major, or as a substitute for B major 7th in jazz. Its tight, bright sound suits bebop and modern jazz.
Changing to and from B augmented major 7th
- Sliding the shape up one fret to the 2nd fret gives C augmented major 7th.
- Sliding the shape up two frets to the 3rd fret gives C♯ augmented major 7th.
Which voicing to use
The F♯♯ inversion places the augmented fifth in the bass, creating a tense, leading tone. The A♯ inversion puts the major seventh in the bass, which darkens the chord and works well for descending lines.
Other B chords
Common questions
How is B augmented major 7th written?
B augmented major 7th is written B+M7, M7#5, maj+7, or BaugM7. It is also called augmented major seventh or major seventh sharp five.
What is the difference between B augmented major 7th and B major 7th?
B augmented major 7th has a raised fifth F♯♯, while B major 7th has a perfect fifth F♯. The raised fifth creates a more dissonant, unstable sound.
Why does B augmented major 7th use a double sharp?
The fifth of B is F♯, so raising it a semitone gives F♯♯, which is enharmonically G. The double sharp keeps the interval name consistent with the scale degree.