Free music analysis

BabylonTone

Know your sound: tempo, key, loudness and tone, measured in seconds.

Drop in your own tracks or pick an Apple Music preview, and BabylonTone measures tempo, key, loudness, brightness and dynamics, or compares a whole album side by side. It runs entirely in your browser, so your files never leave your device. No sign-up.

Drop WAV / MP3 / M4A / FLAC files here, or click to choose.
Select several to compare them as an album.

Want to play in that sound?

Numbers tell you what a track does. One-on-one guitar lessons with Johnny Babylon help you play it, in the sound of the artists you love. Intro lesson $35.

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How it works. Loudness is RMS level in dBFS; brightness is the spectral centroid; tempo comes from autocorrelating a spectral-flux onset curve (60–200 BPM, so half/double-time errors are possible); key is the best match of a pitch-class profile (80–2000 Hz, long frames, each frame normalized) against Krumhansl–Kessler major/minor templates, shown with its Camelot code and the runner-up key. Treat “low confidence” keys as a hint and check the runner-up; half- and double-time tempo readings are listed too. Descriptions are generated by fixed rules from these numbers — no AI and no outside information.