— A major key with 2 flats: Bb, Eb —

The key of Bb major

Scale: Bb · C · D · Eb · F · G · A

Drill key signatures in the trainer →

B♭ major has two flats — B♭ and E♭ — and is the standard key for many wind instruments (trumpet, clarinet, tenor saxophone). Concert-band literature is full of pieces in B♭ for that reason. It sits two steps counter-clockwise from C on the circle of fifths, with G minor as its relative minor.

Key signature

2flats
  1. 1.B♭
  2. 2.E♭

Added in the standard order of flats.

Diatonic chords

The seven triads built on each scale degree. These are the chords you hear used most in Bb major:

RomanChordQualityNotes
IBbmajorBb · D · F
iiCmminorC · Eb · G
iiiDmminorD · F · A
IVEbmajorEb · G · Bb
VFmajorF · A · C
viGmminorG · Bb · D
vii°A°diminishedA · C · Eb

Common progressions

I–V–vi–IV in B♭ is B♭–F–Gm–E♭, common in jazz standards and ballads. The ii–V–I (Cm–F–B♭) is the most-used cadence in jazz, often extended as iii–vi–ii–V–I (Dm–Gm–Cm–F–B♭). Modulation to E♭ major (subdominant) and F major (dominant) is smooth via shared chords.

Relative minor

The relative minor of Bb major is G minor — it shares the same key signature, just centred on the 6th degree of the Bb major scale (G). A piece can move between Bb major and G minor freely without any change of accidentals.

Common mistakes

Beginners sometimes mix up the order of flats: B♭ comes first (it's the only flat in F major, and B♭ major adds E♭). Brass players reading band parts must be careful about transposition — a B♭ trumpet reading in C concert is actually playing in B♭ written. Don't confuse B♭ major (two flats) with its enharmonic A# major, which would require ten sharps and is never used.

Drill it

The Circle of Fifths trainer drills every key signature — Bb major included — with timed flash cards and best-time tracking.

Open the Circle of Fifths Trainer →Or try today's Etudle puzzle

Frequently asked

How many flats does B♭ major have?
B♭ major has two flats: B♭ and E♭.
What are the notes in the B♭ major scale?
B♭, C, D, E♭, F, G, A.
What is the relative minor of B♭ major?
G minor — same two-flat key signature.
What are the chords in the key of B♭ major?
B♭ major (I), C minor (ii), D minor (iii), E♭ major (IV), F major (V), G minor (vi), and A diminished (vii°).