C♭ Major

Key Signature

PropertyValue
TonicC♭
ModeMajor
Accidentals7 flats
Key Signature Notes B♭, E♭, A♭, D♭, G♭, C♭, F♭

C♭ major has seven flats and is enharmonically equivalent to B major. It is theoretically constructed and rarely used in practice but appears in some theoretical contexts.

Diatonic Chords

The seven diatonic chords of C♭ Major — each built on a scale degree using only the notes of the key signature:

DegreeRoman NumeralChord TypeChord
1 I Major C♭ Major
2 ii Minor D♭ Minor
3 iii Minor E♭ Minor
4 IV Major F♭ Major
5 V Major G♭ Major
6 vi Minor A♭ Minor
7 vii° Diminished B♭ Diminished

Related Keys

Relative Minor
A♭ 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 C♭ Major

Common scales built from the C♭ tonic:

Transposing Instrument Context

B♭ instruments (trumpet, clarinet, tenor saxophone) read in D♭ major to sound C♭ Major. E♭ instruments (alto saxophone, E♭ clarinet) read in A♭ major to sound C♭ Major. Flat-key signatures are particularly comfortable for woodwind instruments designed around B♭ and E♭ transpositions.

Related References