Pure tones · 7 forks and more
Online tuning forks
Tap a fork to strike it, hold it to keep it ringing, strike two to hear them beat.
How to use it
- Tap the big fork to strike it: it rings and fades like a real one. Hold it to keep it ringing, and let go to let it ring out. Pick another fork from the row under it, and it strikes too.
- To keep it ringing with your hands free, open More and turn on Keep a fork ringing: it sounds until you tap it again. More also has forks most people never need, your own fork at any Hz with its nearest note, and ringing several together to hear them beat.
Tuning fork frequencies
Every fork here, with the note it gives and who uses it. A fork is named by its note and its frequency in Hz: A440 is an A at exactly 440 Hz.
| Fork | Note | Who uses it |
|---|---|---|
| A440 | A4 | Concert pitch, the international standard |
| A442 | A4 | Many European orchestras |
| A443 | A4 | Some orchestras that tune higher still |
| A415 | A4 | Baroque music on period instruments |
| A432 | A4 | An alternative some people prefer |
| A435 | A4 | France's standard pitch from 1859 |
| A466 | A4 | A high baroque church pitch |
| C256 | C4 | "Scientific" pitch, middle C a power of two |
| C512 | C5 | Hearing tests (Rinne and Weber) |
| C128 | C3 | Doctors' test of vibration sense |
How to tune by ear with a fork
Strike the fork and sound your note against it. Two notes that are nearly the same wobble against each other: that's beating, and the further apart they are, the faster it goes. Move your note until the wobble slows down and disappears.
Ring two forks together here (under More) to hear it plainly: A440 and A442 beat twice a second. For longer listening, a drone holds the note as long as you like.
A short history of concert pitch
Pitch has never stood still. Orchestras and organs in different cities tuned A anywhere from under 400 to over 460 Hz. In 1859 France fixed it at 435 Hz, the diapason normal. A conference in London in 1939 agreed on 440 Hz, and it became the international standard, ISO 16, in 1955.
Today most music is tuned to A440, many orchestras sit a little higher, and baroque players often use A415.
432 Hz, honestly
A432 is a real tuning, about a third of a semitone below A440, and some musicians like its slightly darker sound. What isn't true is that it's more natural or better for your body: there's no good evidence for those claims. If your group tunes there, use it; if not, A440.
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Questions
What frequency is a standard tuning fork?
A440: the A above middle C at 440 Hz. It's the international standard pitch (ISO 16) and the fork most musicians mean.
How do you tune with a tuning fork?
Strike the fork and play or sing the same note. If they're a little apart you hear a slow wobble, called beating. Adjust until it slows and stops. Hold the fork here to keep it ringing while you listen.
What is the difference between 432 Hz and 440 Hz?
A432 is about a third of a semitone lower than A440. It's a real fork, and some people prefer it. Claims that 432 Hz is healthier or more natural have no good evidence behind them; what matters for a group is that everyone uses the same A.
Which fork should I use?
A440 for almost everything: it's concert pitch, and what tuners and pianos use. A442 matches the many orchestras that tune a little higher, and A415 is for baroque music on period instruments.
What is C256, and why C512?
C256 is "scientific" or "philosophical" pitch, where middle C is a power of two. It isn't A440's middle C (261.63 Hz): it implies A at about 430.5 Hz. C512 is the C above it, the classic fork for the Rinne and Weber hearing tests.
Why do baroque groups tune to A415, and orchestras to A442?
Pitch in much of the baroque era was lower than today, and A415, about a semitone below A440, became the usual pitch for period instruments. Many orchestras tune a little above 440, often to 442, which many players say sounds a little brighter.
Why can't I hear the low forks on my phone?
A phone's small speaker barely plays a pure tone as low as C128 or C256. Use headphones for the true tone, or turn on Speaker boost under More, which adds the octave above so it carries.
Can I strike my own frequency?
Yes. Under More, type any frequency from 20 to 4000 Hz and strike it. It names the nearest note against A440, and how many cents sharp or flat your fork is.
Tuning fork, pitch pipe or tuner: which is best for tuning?
A fork gives one pure, steady reference to tune to by ear. A tuner shows you how far off you are. A pitch pipe gives any starting note. For an instrument a tuner is quickest; to train your ear, a fork.
Can I use this for a hearing or medical test?
No. It's a musical reference, not a medical device: a phone can't match a real fork's level or vibration, and those tests are a clinician's job.
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