B0

30.868Hz at concert pitch

Press to hear a pure sine tone at this pitch.
MIDI note
23
Piano key
3
Octave
0
Frequency
30.868 Hz
Period
32.396 ms
Wavelength
11.1118 m
Pitch class
B
Notation
SPN

MIDI is the note number synths and software pass around (0–127). Pitch class is the note without its octave — all the Bs share one.

At other reference pitches

Reference (A4)B0 frequencyWhere you meet it
432 Hz30.306 Hzthe alternative-tuning circle
440 Hzstandard30.868 Hzthe ISO 16 standard — concert pitch
442 Hz31.008 Hzmany European orchestras tune a touch sharp
443 Hz31.078 Hzsome sharper continental orchestras

Every row is B0 — only the A4 you tune to changes. A frequency scales straight with the reference: B0 at 432 Hz is the 440 Hz value times 432⁄440.

Move around

Every B

Chords with B in them

B appears in each of these — see the whole chord grid.