B4
493.883Hz at concert pitch
Press to hear a pure sine tone at this pitch.
MIDI note
71
Piano key
51
Octave
4
Frequency
493.883 Hz
Period
2.0248 ms
Wavelength
0.6945 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) | B4 frequency | Where you meet it |
|---|---|---|
| 432 Hz | 484.904 Hz | the alternative-tuning circle |
| 440 Hzstandard | 493.883 Hz | the ISO 16 standard — concert pitch |
| 442 Hz | 496.128 Hz | many European orchestras tune a touch sharp |
| 443 Hz | 497.251 Hz | some sharper continental orchestras |
Every row is B4 — only the A4 you tune to changes. A frequency scales straight with the reference: B4 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.