# B♭ Major 7th piano chord (B♭maj7)

B♭maj7 contains B♭, D, F and A. A major triad with the major seventh added on top. B♭ is a black key; D, F and A are white.

- Canonical page: https://piano.org/chords/major-7th/b-flat/
- Entity: chord:major-7th:b-flat
- Notes: B♭ D F A
- Formula: 1 3 5 7
- Intervals from root: P1, M3, P5, M7
- Interval stack (semitones): 4 3 4
- Also written: B♭maj7, Bbmaj7, B♭ major 7th
- Parameters: A440, 12-TET, 165 mm octave, spans centre to centre

## Construction

| Degree | Note | Interval from root | Semitones |
| --- | --- | --- | --- |
| 1 | B♭ | Perfect unison | 0 |
| 3 | D | Major third | 4 |
| 5 | F | Perfect fifth | 7 |
| 7 | A | Major seventh | 11 |

## Fingering

Rest your right hand over the notes with finger 2 on B♭, finger 3 on D, finger 4 on F, finger 5 on A. The left hand mirrors it.
Right hand 2-3-4-5, left hand 5-4-3-2. Source: piano.org fingering method v1.

## Inversions

| Position | Bass | Notes in order | Figured bass | Span |
| --- | --- | --- | --- | --- |
| Root position | B♭ | B♭3 D4 F4 A4 | 7 | 11 st, 151 mm |
| First inversion (B♭maj7/D) | D | D4 F4 A4 B♭4 | 6/5 | 8 st, 110 mm |
| Second inversion (B♭maj7/F) | F | F4 A4 B♭4 D5 | 4/3 | 9 st, 124 mm |
| Third inversion (B♭maj7/A) | A | A4 B♭4 D5 F5 | 4/2 | 8 st, 110 mm |

## Voicings (10)

| Voicing | Notes | Span | Relation | Omits or adds |
| --- | --- | --- | --- | --- |
| Close, root position | B♭3 D4 F4 A4 | 11 st, 151 mm | identical | none |
| Close, first inversion | D4 F4 A4 B♭4 | 8 st, 110 mm | identical | none |
| Close, second inversion | F4 A4 B♭4 D5 | 9 st, 124 mm | identical | none |
| Close, third inversion | A4 B♭4 D5 F5 | 8 st, 110 mm | identical | none |
| Drop 2 | F3 B♭3 D4 A4 | 16 st, 220 mm | identical | none |
| Drop 3 | D3 B♭3 F4 A4 | 19 st, 261 mm | identical | none |
| Drop 2 and 4 | B♭2 F3 D4 A4 | 23 st, 316 mm | identical | none |
| Shell, root 7 3 | B♭2 A3 D4 | 16 st, 220 mm | subset | omits F |
| Guide tones, 3 and 7 | D4 A4 | 7 st, 96 mm | subset | omits B♭ and F |
| Rootless close | D4 F4 A4 | 7 st, 96 mm | subset | omits B♭ |

## Diatonic function by key

| Key | Roman numeral | Function |
| --- | --- | --- |
| D minor | ♭VImaj7 | Pre-dominant colour |
| F major | IVmaj7 | Subdominant, away from home |
| G minor | ♭IIImaj7 | Relative-major colour |
| B♭ major | Imaj7 | Tonic, home |

Classification system: common-practice functional harmony.

## Progressions (9)

| Progression | Key | Role | Sequence | Voice leading |
| --- | --- | --- | --- | --- |
| ♭VI, iv, i, v | D minor | ♭VImaj7 | B♭maj7 to Gm7 to Dm7 to Am7 | B♭maj7 opens the phrase |
| i, ♭VI | D minor | ♭VImaj7 | Dm7 to B♭maj7 | 3 tones held from Dm7 |
| IV, V, I | F major | IVmaj7 | B♭maj7 to C7 to Fmaj7 | B♭maj7 opens the phrase |
| I, IV | F major | IVmaj7 | Fmaj7 to B♭maj7 | 2 tones held from Fmaj7 |
| ♭III, ♭VI, ii, v | G minor | ♭IIImaj7 | B♭maj7 to E♭maj7 to Am7♭5 to Dm7 | B♭maj7 opens the phrase |
| i, ♭III | G minor | ♭IIImaj7 | Gm7 to B♭maj7 | 3 tones held from Gm7 |
| ii, V, I | B♭ major | Imaj7 | Cm7 to F7 to B♭maj7 | 2 tones held from F7 |
| IV, I | B♭ major | Imaj7 | E♭maj7 to B♭maj7 | 2 tones held from E♭maj7 |
| I, vi, ii, V | B♭ major | Imaj7 | B♭maj7 to Gm7 to Cm7 to F7 | B♭maj7 opens the phrase |

## One-edit neighbors

| Becomes | Edit | Changes | Common tones |
| --- | --- | --- | --- |
| B♭maj9 | 1 3 5 7 9 | adds C | 4 |
| B♭ | 1 3 5 | drops A | 3 |
| B♭7 | 1 3 5 ♭7 | A becomes A♭ | 3 |
| B♭mMaj7 | 1 ♭3 5 7 | D becomes D♭ | 3 |
| B♭6 | 1 3 5 6 | A becomes G | 3 |
| B♭add9 | 1 3 5 9 | A becomes C | 3 |
| B♭9 | 1 3 5 ♭7 9 | A becomes A♭, C | 3 |
| B♭m | 1 ♭3 5 | D, A becomes D♭ | 2 |
| B♭aug | 1 3 ♯5 | F, A becomes F♯ | 2 |
| B♭sus2 | 1 2 5 | D, A becomes C | 2 |
| B♭sus4 | 1 4 5 | D, A becomes E♭ | 2 |
| B♭m7 | 1 ♭3 5 ♭7 | D, A becomes D♭, A♭ | 2 |

## Set theory

- Absolute pitch classes: {10, 2, 5, 9}
- Relative pitch classes: [0, 4, 7, 11]
- Normal order: [9, 10, 2, 5]
- Prime form: (0158)
- Forte number: 4-20
- Interval vector: <101220>

## Frequencies (close root position)

| Note | MIDI | Frequency |
| --- | --- | --- |
| B♭3 | 58 | 233.08 Hz |
| D4 | 62 | 293.66 Hz |
| F4 | 65 | 349.23 Hz |
| A4 | 69 | 440.00 Hz |

## Questions and answers

### What notes are in B♭maj7?

B♭maj7 contains B♭, D, F and A. The formula is 1, 3, 5, 7.

### How do you play B♭maj7 on piano?

Play B♭, D, F and A together. Right hand fingers 2, 3, 4, 5; left hand 5, 4, 3, 2. B♭ is a black key; D, F and A are white.

### What are the inversions of B♭maj7?

4 positions: root position B♭ D F A, B♭maj7/D, B♭maj7/F, B♭maj7/A.

### What keys contain B♭maj7?

4: ♭VImaj7 in D minor, IVmaj7 in F major, ♭IIImaj7 in G minor, Imaj7 in B♭ major.

### What is the difference between B♭maj7 and B♭maj9?

Adds C. 4 of the notes are shared.

### What is an easy B♭maj7 for small hands?

The guide tones, 3 and 7 voicing, D4 A4, spans 7 semitones or about 96 mm.

### What are the frequencies of B♭maj7?

From B♭3 at A440 in 12-TET: 233.08, 293.66, 349.23, 440.00 Hz.

### What is the set class of B♭maj7?

Prime form (0158), Forte 4-20, interval vector &lt;101220&gt;.

### How do I transpose B♭maj7 to another key?

Keep the 1, 3, 5, 7 formula on the new root. Cmaj7 is C, E, G, B; C♯maj7 is C♯, E♯, G♯, B♯.

### Is A♯maj7 the same as B♭maj7?

Enharmonically yes: the same piano keys and the same sound, spelled differently.

## Provenance

Every derived value above is computed by the piano.org theory kernel from the root, the quality and the stated parameters. Nothing is hand-entered per chord.

Machine record: https://piano.org/api/knowledge/v1/entities/chord:major-7th:b-flat
Last reviewed: 2026-08-12