Reference Pitch Player

How to use it

1. Choose the tuning standard: A4 at 440, 442, 443 or 415 Hz.
2. Pick the pitch and octave, then a sine or triangle waveform.
3. Press Play to hold the tone, or switch to Pulse for short repeated beeps. Press Stop when you are done.
4. To check a tuner or your voice, type the frequency it shows into the cents box. The tool tells you how many cents sharp or flat you are.
5. To practise singing, press Sing this note. You hear the pitch, get a three second countdown, then sing in silence until the timer ends.

What the numbers mean

Pitch is measured in hertz, the number of vibrations per second. Equal temperament divides the octave into 12 equal semitones, so each semitone multiplies the frequency by the twelfth root of 2. From the reference A4, the frequency of any note is A4 times 2 to the power of the semitone distance divided by 12.

A cent is one hundredth of a semitone. Cents are the standard way to describe how far a note is from the target, because they work the same at every pitch. The offset is 1200 times the base 2 logarithm of the ratio of the two frequencies. For example, 442 Hz against 440 Hz is about 7.85 cents sharp.

Sine or triangle

A sine wave has a single pure frequency and is the easiest to match by ear and to read on a tuner. A triangle wave adds soft upper harmonics, which makes the tone easier to hear on small phone speakers and closer to a flute or a voice. Pick whichever you can hear and match comfortably.

Using it to practise singing

The sing mode plays the target note, counts you in, then goes silent while you hold the pitch. That removes the reference at the exact moment you need to rely on your ear. Afterwards, enter the frequency from a tuner app to see how many cents off you were, and try to get closer on the next round.

Common questions

Why does my tuner read a little different from the tool?

Check the A4 setting. If your tuner is calibrated to 442 and this tool is on 440, every note is about 7.85 cents apart. Also, speakers and microphones can shift readings slightly, especially at low pitches, so compare in a quiet room.

What is the difference between 440 and 415?

415 Hz is the usual baroque pitch, about a semitone below modern pitch. Players of harpsichords and period strings tune to it so the instruments sound as they did when the music was written.

How many cents is too far off?

Most listeners hear a note as out of tune from about 10 to 20 cents, depending on the context and the instrument. Singers and string players usually aim to stay within 5 to 10 cents of the target.

Why does the tone stop when I leave the page?

The tool stops sound when the tab is hidden or the page is closed, so a tone never keeps playing in the background. Browsers also require a button press before audio can start, which is why nothing plays until you press Play.