B♭ (musical note)

B♭ (B-flat; also called si bémol) is the first note of the B♭ minor scale. It is also enharmonic to A-sharp.

B Flat

For other uses, see B-flat.

Designation by octave

Scientific designation	Helmholtz designation	Octave name	Frequency (Hz)
B♭−1	B♭͵͵͵ or ͵͵͵B♭ or BBBB♭	Subsubcontra	14.568
B♭0	B♭͵͵ or ͵͵B♭ or BBB♭	Subcontra	29.135
B♭1	B♭͵ or ͵B♭ or BB♭	Contra	58.27
B♭2	B♭	Great	116.541
B♭3	b♭	Small	233.082
B♭4	b♭′	One-lined	466.164
B♭5	b♭′′	Two-lined	932.328
B♭6	b♭′′′	Three-lined	1864.655
B♭7	b♭′′′′	Four-lined	3729.31
B♭8	b♭′′′′′	Five-lined	7458.62
B♭9	b♭′′′′′′	Six-lined	14917.24
B♭10	b♭′′′′′′′	Seven-lined	29834.481

Common scales beginning on B♭

• B-flat major: B♭ C D E♭ F G A B♭
• B-flat natural minor: B♭ C D♭ E♭ F G♭ A♭ B♭
• B-flat harmonic minor: B♭ C D♭ E♭ F G♭ A B♭
• B-flat melodic minor ascending: B♭ C D♭ E♭ F G A B♭
• B-flat melodic minor descending: B♭ A♭ G♭ F E♭ D♭ C B♭