A7 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 | A7 | vs 440 |
|---|---|---|
| A4 = 415 Hz · Baroque pitch | 3320.0 Hz | −101.3¢ |
| A4 = 432 Hz · “Verdi” pitch | 3456.0 Hz | −31.8¢ |
| A4 = 440 Hz · Standard (ISO 16) | 3520.0 Hz | — |
| A4 = 442 Hz · Orchestral | 3536.0 Hz | +7.9¢ |
One cycle of A7 lasts 284.1 µs, and its wavelength in air at 20 °C is 9.7 cm. Hold it as a steady tone in the tone generator.
A7 on the piano
A7 is key 85 of 88, counting from the bottom — a white key. Press any key below to compare it with its neighbours.
A7 on the guitar
A7 is above the highest fret of any standard guitar, so a guitar in standard tuning cannot play it.
A7 on the staff
Instruments that can play A7
5 instruments play A7 within the normal range, and 1 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.
Bowed strings
Woodwind
Tuned percussion
Keyboards and free reeds
Only at the extreme of their range
A7 is outside the typical range of all six voice types. Test your own range.
The harmonics of A7
A played A7 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) | 3520.0 Hz | A7 | 0¢ |
| 2 | 7040.0 Hz | A8 | 0¢ |
| 3 | 10,560 Hz | E9 | +2.0¢ |
| 4 | 14,080 Hz | A9 | 0¢ |
| 5 | 17,600 Hz | C♯10 | −13.7¢ |
| 6 | 21,120 Hz | E10 | +2.0¢ |
| 7 | 24,640 Hz | G10 | −31.2¢ |
| 8 | 28,160 Hz | A10 | 0¢ |
Frequently asked questions
What is the frequency of A7?
A7 is 3520.0 Hz in equal temperament with A4 tuned to 440 Hz, the international standard. At A4 = 432 Hz it is 3456.0 Hz, and at the orchestral A4 = 442 Hz it is 3536.0 Hz.
Which octave is A7 in?
The number is the octave in scientific pitch notation, where each octave starts on C and C4 is middle C. A7 is in octave 7, 45 semitones above middle C. In Helmholtz notation, used in older books, it is written a′×4.
How do I play A7 on a piano?
A7 is key 85 of 88, counting from the bottom — a white key.
Which instruments can play A7?
5 of the instruments we chart play A7 within their normal range, including erhu, piccolo, xylophone, glockenspiel, piano, and 1 more reach it only at the extreme of their range.
Typing it? A7 is also written A7. Convert any frequency on the Hz-to-note converter.