DJ Harmonic Assistant

About

DJ Harmonic Assistant tells you the musical key and tempo of whatever you're
listening to on SoundCloud — instantly, on any track, computed right in your browser.

Press the toolbar button (or Ctrl+Shift+K) while a track plays and within about 30
seconds you'll see:

• The key in Camelot notation (e.g. 8A) and standard notation (e.g. A minor)
• The BPM (tempo), octave-normalised to a DJ-friendly range
• A confidence indicator for the detection
• How well it harmonically mixes with your reference track — pin any analysed track
  as the reference and every new one is compared against it
• A "wrong key?" override if you disagree with the detection
• A list of recently analysed tracks and quick links to dig deeper

Everything is processed locally using on-device audio analysis. No account, no
sign-up, no servers, no analytics. The audio of the tab you choose to analyse never
leaves your computer.

Note: not affiliated with SoundCloud. Works on soundcloud.com.