Key signature · 2♭
B♭ major key signature and G minor
B♭ major and its relative minor, G minor, share a key signature of two flats: B♭ and E♭.
- Flats2
- WhichB♭ E♭
- Relative minorG minor
- Home chordB♭–D–F
The key signature
The flats come right after the clef, on every line of music. In the treble clef: B♭ on the middle line and E♭ on the top space. In the bass clef the same flats appear, in the same order, on the bass staff’s B and E.
Each one changes that letter everywhere in the piece, in every octave and on both staves: in B♭ major, every B and E is flat, though no sign is written beside the note.
How to recognise it quickly
Look at the second-to-last flat: B♭. That’s the name of the major key, B♭ major. For the minor key, go down three half steps: G minor.
Flats always come in the same order, so two flats are always B♭ and E♭:
- B♭
- E♭
- A♭
- D♭
- G♭
- C♭
- F♭
Battle Ends And Down Goes Charles’ Father: the order of flats, the order of sharps backwards.
The B♭ major scale
B♭ – C – D – E♭ – F – G – A – B♭. On the piano that’s two black keys (B♭ and E♭) and five white (C, D, F, G and A). Its home chord is B♭–D–F.
More on this key: the B♭ major scale with fingering · the B♭ major chord
G minor, the relative minor
G minor uses the same two flats, starting from G, the sixth note of B♭ major: G – A – B♭ – C – D – E♭ – F – G. That’s the natural minor scale. Its home chord is G–B♭–D.
Pieces in G minor usually raise the seventh note, F, to F♯ (the harmonic minor), so it leads up to G. That F♯ is written as an accidental, not in the key signature: the sharp beside the note is often the quickest clue that a piece is in G minor rather than B♭ major. Pieces also often begin or end on G or its chord.
More on this key: G minor natural minor · G minor harmonic minor · the G minor chord
Music in B♭ major and G minor
Schubert’s Impromptu D. 935 No. 3, a theme with variations, is in B♭ major.
Mozart’s Symphony No. 40 and Chopin’s Ballade No. 1 are both in G minor.
On the circle of fifths
One flat fewer is F major, a fifth higher; one flat more is E♭ major, a fifth lower. Keys next to each other on the circle of fifths share all but one note, which is why music in B♭ major moves to them most easily.
B♭ minor, with the same home note but a minor scale, has a different key signature: five flats, the same as D♭ major.
Quiz: name the key signature
Ten key signatures in the treble or bass clef, from all fifteen. Choose the key, or play its home note on the piano below, a MIDI keyboard or your computer keys (any octave).
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Questions
How many flats are in B♭ major?
Two flats: B♭ and E♭. Every B and E in the piece is played flat, in every octave, unless an accidental says otherwise.
What is the relative minor of B♭ major?
G minor. It shares the key signature (two flats (B♭ and E♭)) and starts on the sixth note of the B♭ major scale, three half steps below B♭.
What are the notes of the B♭ major scale?
B♭, C, D, E♭, F, G, A, B♭.
Which key has two flats?
B♭ major and its relative minor, G minor.
How do you recognise the B♭ major key signature quickly?
Look at the second-to-last flat: B♭. That’s the name of the major key, B♭ major. For the minor key, go down three half steps: G minor.
Keys, one at a time
Pianomi, a free sight-reading app for piano, brings in key signatures one at a time and notices when you play a note as if the key signature weren’t there.