B♭ Major
Key Signature
| Property | Value |
|---|---|
| Tonic | B♭ |
| Mode | Major |
| Accidentals | 2 flats |
| Key Signature Notes | B♭, E♭ |
B♭ major has two flats (B♭, E♭) and is extremely common in jazz and wind ensemble music. It is the home key for B♭ instruments such as the trumpet and tenor saxophone.
Diatonic Chords
The seven diatonic chords of B♭ Major — each built on a scale degree using only the notes of the key signature:
| Degree | Roman Numeral | Chord Type | Chord |
|---|---|---|---|
| 1 | I | Major | B♭ Major |
| 2 | ii | Minor | C Minor |
| 3 | iii | Minor | D Minor |
| 4 | IV | Major | E♭ Major |
| 5 | V | Major | F Major |
| 6 | vi | Minor | G Minor |
| 7 | vii° | Diminished | A Diminished |
Related Keys
- Relative Minor
- G Minor — shares the same key signature.
- Parallel Minor
- B♭ Minor — same tonic, different key signature.
See all key relationships on the Circle of Fifths.
Scales in B♭ Major
Common scales built from the B♭ tonic:
Transposing Instrument Context
B♭ instruments (trumpet, clarinet, tenor saxophone) read in C major to sound B♭ Major. E♭ instruments (alto saxophone, E♭ clarinet) read in G major to sound B♭ Major. Flat-key signatures are particularly comfortable for woodwind instruments designed around B♭ and E♭ transpositions.