The B♭ Note
B♭ is a black key, immediately next to B. It sounds at 466.16 Hz in octave 4.
B♭ on the piano
Key facts
- On the keyboard
- a black key, immediately next to B.
- Frequency (octave 4)
- 466.16 Hz
- MIDI number (octave 4)
- 70
- Also written as
- A♯
- In key signatures
- The 1 flat in the order of flats.
B♭ and its enharmonic spellings
B♭ can also be written as A♯. These are enharmonic equivalents: the same pitch, the same key on the piano, a different name on the page. Which spelling is correct depends on the key and on how the note functions, not on the sound.
B♭ frequency in every octave
Frequencies for B♭ in scientific pitch notation, with A4 tuned to 440 Hz.
| Note | MIDI | Frequency |
|---|---|---|
| B♭1 | 34 | 58.27 Hz |
| B♭2 | 46 | 116.54 Hz |
| B♭3 | 58 | 233.08 Hz |
| B♭4 | 70 | 466.16 Hz |
| B♭5 | 82 | 932.33 Hz |
| B♭6 | 94 | 1864.66 Hz |
| B♭7 | 106 | 3729.31 Hz |
Chords on B♭
The most common chords built with B♭ as the root.
Scales starting on B♭
Keys and scales that use B♭ as their tonic.
All notes
Frequently asked questions
Where is B♭ on the piano?
B♭ is a black key, immediately next to B.
What frequency is B♭4?
B♭4 sounds at 466.16 Hz with A4 tuned to 440 Hz.
What is another name for B♭?
B♭ can also be written as A♯. They are the same pitch spelled differently.
