Free music theory tools
Online tools for every stage of the songwriting process. Free, instant, and no signup required.
Circle of Fifths
Interactive Circle of Fifths. Click any key to instantly see its diatonic chords, relative minor, and neighbouring key relationships.
circle of fifths, key relationships, diatonic chords
Chord Transposer
Shift any chord progression to any key in one click. Perfect for finding the right key for your voice or instrument.
transpose chords, change key, chord transposition
Key Detector
Enter a progression and detect the musical key it belongs to. Understand the tonal center of any chord sequence.
key detector, find key, musical key
Related reading
Need the full editor?
Combine all these tools in the Chord Player — drag chords, pick styles, and export to WAV.
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