B4 at every common reference pitch
A note’s frequency depends on what A4 is tuned to. The standard is 440 Hz; the other three are the ones you are most likely to meet. The cents column is how far each one sits from the 440 version — the same for every note, because changing the reference moves the whole scale together.
| Reference | B4 | vs 440 |
|---|---|---|
| A4 = 415 Hz · Baroque pitch | 465.82 Hz | −101.3¢ |
| A4 = 432 Hz · “Verdi” pitch | 484.90 Hz | −31.8¢ |
| A4 = 440 Hz · Standard (ISO 16) | 493.88 Hz | — |
| A4 = 442 Hz · Orchestral | 496.13 Hz | +7.9¢ |
One cycle of B4 lasts 2.025 ms, and its wavelength in air at 20 °C is 69.4 cm. Hold it as a steady tone in the tone generator.
B4 on the piano
B4 is key 51 of 88, counting from the bottom — a white key. Press any key below to compare it with its neighbours.
B4 on the guitar
In standard tuning B4 is played in 3 places: 3rd (G) string, fret 16, 2nd (B) string, fret 12 and 1st (high E) string, fret 7. The same pitch in each place, with a different tone: lower strings sound warmer. Guitar music is written an octave higher than it sounds, so on a guitar part this note is printed as B5.
B4 on the staff
Instruments that can play B4
43 instruments play B4 within the normal range, and 4 reach it only at the extreme of theirs. Each links to its range chart; for a transposing instrument, the note on its part is shown.
Guitars and basses
Plucked and struck strings
Woodwind
Brass
Tuned percussion
Only at the extreme of their range
Voices: B4 is inside the typical range of the tenor, alto, mezzo-soprano and soprano. Test your own range.
The harmonics of B4
A played B4 is not one frequency. A string or a pipe also sounds whole-number multiples of it, and the mix of those harmonics is the instrument’s tone. Here is where the first eight land — and why the 7th sounds out of tune against a piano.
| Harmonic | Frequency | Nearest note | Off by |
|---|---|---|---|
| 1 (fundamental) | 493.88 Hz | B4 | 0¢ |
| 2 | 987.77 Hz | B5 | 0¢ |
| 3 | 1481.6 Hz | F♯6 | +2.0¢ |
| 4 | 1975.5 Hz | B6 | 0¢ |
| 5 | 2469.4 Hz | E♭7 | −13.7¢ |
| 6 | 2963.3 Hz | F♯7 | +2.0¢ |
| 7 | 3457.2 Hz | A7 | −31.2¢ |
| 8 | 3951.1 Hz | B7 | 0¢ |
Frequently asked questions
What is the frequency of B4?
B4 is 493.88 Hz in equal temperament with A4 tuned to 440 Hz, the international standard. At A4 = 432 Hz it is 484.90 Hz, and at the orchestral A4 = 442 Hz it is 496.13 Hz.
Which octave is B4 in?
The number is the octave in scientific pitch notation, where each octave starts on C and C4 is middle C. B4 is in octave 4, 11 semitones above middle C. In Helmholtz notation, used in older books, it is written b′.
How do I play B4 on a piano?
B4 is key 51 of 88, counting from the bottom — a white key.
Which instruments can play B4?
43 of the instruments we chart play B4 within their normal range, including violin, viola, cello, erhu, guitar, and 4 more reach it only at the extreme of their range.
Typing it? B4 is also written B4. Convert any frequency on the Hz-to-note converter.