B♭ (musical note)

B♭ (musical note)

B (B-flat; also called si bémol) is the eleventh semitone of the Western chromatic scale (starting from C).

It lies a diatonic semitone above A and a chromatic semitone below B, thus being enharmonic to A although in some musical tunings, B will have a different sounding pitch than A.

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. See pitch (music) 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 provided by a tuba, horn, or clarinet.

In Germany, Russia, Poland and Scandinavia 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. See B (musical note) for an explanation.

Designation by octave

Scientific designation Helmholtz designation Bilinear music notation Octave name Frequency (Hz)
B-1 B͵͵͵ or ͵͵͵B or BBBB (-uB) Subsubcontra 14.568
B0 B͵͵ or ͵͵B or BBB (-vB) Subcontra 29.135
B1 B͵ or ͵B or BB (-wB) Contra 58.270
B2 B (-xB) Great 116.541
B3 b (-yB) Small 233.082
B4 b (zB) One-lined 466.164
B5 b′′ (yB) Two-lined 932.328
B6 b′′′ (xB) Three-lined 1864.655
B7 b′′′′ (wB) Four-lined 3729.310
B8 b′′′′′ (vB}) Five-lined 7458.620
B9 b′′′′′′ (uB) Six-lined 14917.240
B10 b′′′′′′′ (tB) Seven-lined 29834.481


Common scales beginning on B

Diatonic scales

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

Jazz Melodic Minor

See also