B♭ (musical note)

B♭ (B-flat), or, in some European countries, B, is the eleventh step of the Western chromatic scale (starting from C). It lies a diatonic semitone above A and a chromatic semitone below B,^[1] thus being enharmonic to A♯, even though in some musical tunings, B♭ will have a different sounding pitch than A♯. B-flat is also enharmonic to C (C-double flat).

B Flat notes

When calculated in equal temperament with a reference of A above middle C as 440 Hz, the frequency of the B♭ above middle C is approximately 466.164 Hz.^[2] See musical pitch for a discussion of historical variations in frequency.

While orchestras tune to an A provided by the oboist, wind ensembles usually tune to a B-flat.^[3]

In Germany, Russia, Poland, Scandinavia and Slovakia this pitch is designated B, with 'H' used to designate the B-natural. Since the 1990s, B-flat is often denoted Bb or "Bess" instead of B in Swedish music textbooks. Natural B is called "B" by Swedish jazz and pop musicians, but still denoted H in classical music.^[4] See B (musical note) and Note names and their history for explanations.

Designation by octave

Scientific designation	Helmholtz designation	Octave name	Frequency (Hz)	MIDI note number
B♭−1	B♭͵͵͵ or ͵͵͵B♭ or BBBB♭	Subsubcontra	14.568	10
B♭0	B♭͵͵ or ͵͵B♭ or BBB♭	Subcontra	29.135	22
B♭1	B♭͵ or ͵B♭ or BB♭	Contra	58.27	34
B♭2	B♭	Great	116.541	46
B♭3	b♭	Small	233.082	58
B♭4	b♭′	One-lined	466.164	70
B♭5	b♭′′	Two-lined	932.328	82
B♭6	b♭′′′	Three-lined	1864.655	94
B♭7	b♭′′′′	Four-lined	3729.31	106
B♭8	b♭′′′′′	Five-lined	7458.62	118
B♭9	b♭′′′′′′	Six-lined	14917.24	N/A
B♭10	b♭′′′′′′′	Seven-lined	29834.481	N/A

Scales

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♭

Diatonic scales

• B-flat Ionian: B♭ C D E♭ F G A B♭
• B-flat Dorian: B♭ C D♭ E♭ F G A♭ B♭
• B-flat Phrygian: B♭ C♭ D♭ E♭ F G♭ A♭ B♭
• B-flat Lydian: B♭ C D E F G A B♭
• B-flat Mixolydian: B♭ C D E♭ F G A♭ B♭
• B-flat Aeolian: B♭ C D♭ E♭ F G♭ A♭ B♭
• B-flat Locrian: B♭ C♭ D♭ E♭ F♭ G♭ A♭ B♭

Jazz melodic minor

• B-flat ascending melodic minor: B♭ C D♭ E♭ F G A B♭
• B-flat Dorian ♭2: B♭ C♭ D♭ E♭ F G A♭ B♭
• B-flat Lydian augmented: B♭ C D E F♯ G A B♭
• B-flat Lydian dominant: B♭ C D E F G A♭ B♭
• B-flat Mixolydian ♭6: B♭ C D E♭ F G♭ A♭ B♭
• B-flat Locrian ♮2: B♭ C D♭ E♭ F♭ G♭ A♭ B♭
• B-flat altered: B♭ C♭ D♭ E F♭ G♭ A♭ B♭