How this key and BPM finder works

To practice checking a key and BPM result, choose Try a sample in the audio analyzer, listen to the 32-second synthetic clip, compare the candidates with its 120 BPM, A minor, Camelot 8A reference, then copy the checked result. This teaching exercise is not evidence of accuracy on other music; practice changes are not saved or submitted.

Use the audio analyzer alongside this guide. Returning to the analyzer loads a new page, so choose your audio again. Keep this guide open in a separate tab if you want to follow the steps while listening.

How to find the key of a song

Start with a local MP3 or WAV that has audible melody, bass, or chords. Listen for the note that phrases settle on, then check whether the harmony supports major or minor. C major and A minor share scale notes, so a matching note list is not enough. The full methods — by ear, from chords, and from a file — are in how to find the key of a song.

Camelot is another name for the selected key: A minor is 8A and C major is 8B. See Camelot wheel explained. Tempo is a separate check: find the BPM of a song. If you already have chords, use the key finder from chords. Delay times from a BPM are on the BPM to milliseconds calculator.

Synthetic teaching example

Try a 120 BPM, A minor practice clip

This original 32-second clip was generated for this exercise. Its reference tempo and key come from the synthesis settings: 120 BPM · A minor · 8A. It is not a real song or evidence of accuracy on other music. You may freely use the clip.

  1. Try the input. Open the audio analyzer and choose Try a sample. It loads this clip and runs the real analysis in your browser; practice changes are not saved or submitted. You can also Download the teaching WAV (1.41 MB) to keep a copy.

  2. Compare the candidate with the reference. This version returned 120 BPM, A minor, and 8A in our Chrome check. Press Play audio and count the steady pulse. The numerical match shows this exercise worked, not that every future detection will be right.

  3. Practice checking a half-tempo reading. Choose Half: the result becomes 60 BPM while the audio keeps playing at its original speed. Count every other beat to hear that interpretation. Choose Double to return to the clip's 120 BPM reference. No correction submission is needed for this exercise.

  4. Copy the checked values. Choose Copy result. After the Half/Double exercise, the copied text identifies the result as adjusted:

    120 BPM · A minor · Camelot 8A (manually adjusted)

    Before any changes, the same values are labeled “algorithm candidates.” To undo practice changes, open Correct result and choose Restore detected values.

Back to Choose audio

When the result needs a second look

70 or 140 BPM: which pulse are you counting?

Play a steady passage and count “1, 2, 3, 4” with the pulse you want to use in your project. Try counting twice as often, then half as often. A 70 BPM pulse is about 0.86 seconds apart; 140 BPM is about 0.43 seconds apart. Both readings can describe different levels of the same rhythm.

In the audio analyzer, choose Check tempo by tapping beside your BPM result to check your count. Choose Half or Double if that value fits. The inline tap check keeps your file; applying a tapped value requires Apply to current audio. These controls change the result, not playback speed. Check the choice against a metronome in your music software before arranging a long track.

Unclear key: find pitched evidence first

Use the playback slider to listen where bass, chords, or melody are present. Compare with the notes and chords in the source project, a reliable reference for this exact recording, or a keyboard. Listen for the tonal center and whether the harmony supports major or minor; one matching note is not enough. A Low confidence result still gives a main key and two alternatives to compare by ear. The percentage is the finder's estimate for this file, not a measured accuracy rate.

The slider changes what you hear, not which part is analyzed. To analyze a passage separately, export it as an MP3 or WAV of at least four seconds in your own editor, then choose that file in the audio analyzer. If the result is Low confidence, compare its main key and two alternatives before correcting it. The key is Unclear only when the audio has no usable pitched evidence. To remove an unsupported key, open Correct result, select Unclear, and save; Camelot is removed too. Saving shares the correction details and audio identifier as explained beside the save button.

A song changes tempo or key halfway through

Listen near the start, middle, and end. A single BPM or key cannot describe every section of a changing song. For files longer than 90 seconds, this tool samples 30-second sections from the beginning, middle, and end; it does not build a tempo map or mark key changes on the waveform.

Export the sections you need in your audio editor and analyze them separately. Keep a note of which section each copied result describes. For a live performance with changing timing, work with your editor's tempo mapping or manual alignment rather than forcing the entire recording to match one estimate.

Take a checked result into your project

Check more than the first few beats

Set your project to the candidate BPM, align the audio's first downbeat, and compare it with the metronome over several phrases. A constant offset suggests a start-position issue. A steadily growing offset suggests a tempo mismatch; drift that begins at one section can signal a timing change there. Check the recording before adjusting the number again.

For example, in Ableton Live 12, turn the clip's Warp switch off to compare its original timing against the project tempo. With Warp on, the clip can follow the project tempo, so alignment alone would not verify its original BPM. See Ableton's warping guide.

Use Key and Camelot as references

An A minor result is shown as 8A in Camelot. These are two names for the same selected key, not two independent checks. Use them to choose something to audition, then listen to the overlapping bass, melody, and chords. Matching codes do not guarantee that two recordings will work together.

Copy tempo, Copy key, and Copy Camelot copy individual values. Copy result includes whether the values are algorithm candidates or manually adjusted; when a key is found, it also includes the two Also possible keys. None of these actions changes the source file, its tags, pitch, or tempo.

Back to the audio analyzer