B major 7th chord on bass (Bmaj7)

Also called or written Bmaj7 or BM7

B major 7th contains B, D♯, F♯, and A♯. The 7th-fret shape demands a wide pinky stretch across four frets.

7frBF♯A♯D♯EADG
Positions on the neck1 of 4
Practice B major 7th chord

How it is built

BRootD♯Major thirdF♯Perfect fifthA♯Major seventh

Formula 1, 3, 5, 7

Inversions

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

B major 7th is played at the 7th fret as 7 9 8 8: index finger on the E string at fret 7, pinky finger on the A string at fret 9, middle finger on the D string at fret 8 and ring finger on the G string at fret 8.

Full note and interval breakdown
StringFretFingerNote
4 (E)71B (1)
3 (A)94F♯ (5)
2 (D)82A♯ (7)
1 (G)83D♯ (3)

AdvancedThe pinky must reach the 9th fret on the 3rd string while the index stays at the 7th fret, stretching the hand.

Bmaj7/F♯ inversion · fret 1

B major 7th is played at the 1st fret as 2 2 1 3: middle finger on the E string at fret 2, ring 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
StringFretFingerNote
4 (E)22F♯ (5)
3 (A)23B (1)
2 (D)11D♯ (3)
1 (G)34A♯ (7)

Bmaj7/F♯ inversion · fret 13

B major 7th is played at the 13th fret as 14 14 13 15: middle finger on the E string at fret 14, ring 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
StringFretFingerNote
4 (E)142F♯ (5)
3 (A)143B (1)
2 (D)131D♯ (3)
1 (G)154A♯ (7)

Bmaj7/A♯ inversion

B major 7th is played at the 4th fret as 6 6 4 4: ring finger on the E string at fret 6, pinky finger on the A string at fret 6, index finger on the D string at fret 4 and middle finger on the G string at fret 4.

Full note and interval breakdown
StringFretFingerNote
4 (E)63A♯ (7)
3 (A)64D♯ (3)
2 (D)41F♯ (5)
1 (G)42B (1)

Why it sounds like that

B major 7th is built from the 1, 3, 5, and 7 of the B major scale. The major 7th interval from B to A♯ gives the chord its bright, resolved quality. Compare it to B major, which omits the A♯ and sounds more plain.

What goes wrong with B major 7th?

  • Letting the pinky mute the 2nd string by lying flat.
  • Allowing the index finger to roll off the 4th string.
  • Plucking the 1st string too hard and making the A♯ ring out harshly.

When to use it

B major 7th is the I chord in B major, as in B–E–F♯–B, the I–IV–V–I. It works for jazz fusion, progressive rock, and atmospheric pop. Use it over B major or B 5th.

Changing to and from B major 7th

  • Sliding the shape down two frets to the 5th fret gives A major 7th.
  • From B major 7th, move the pinky from the 3rd string 9th fret to the 2nd string 8th fret to play B major.

Which voicing to use

The 7th-fret shape places B in the bass for a strong root position. The Bmaj7/F♯ inversion at the 2nd fret has F♯ in the bass, giving a lighter feel. The Bmaj7/A♯ inversion at the 6th fret puts the leading tone A♯ in the bass, creating tension that resolves to B.

Other B chords

Common questions

How is B major 7th written?

B major 7th is written BM7 or Bmaj7.

What is the most common mistake with B major 7th?

Bassists often let the pinky collapse and buzz the 3rd string. Keep the pinky curved and press firmly.

How does B major 7th sound in a higher register?

Playing B major 7th at the 14th fret gives a brighter, more shimmering tone. The same notes ring out with less low-end weight.

Why is B major 7th sometimes confused with B major?

B major 7th adds the A♯, the major 7th, to the B major triad. That extra note creates a dreamier, more resolved sound than B major.