Explore diatonic chords in any key, scale, and mode using a virtual keyboard you can play with your computer keys or mouse. Switch between 9 scales (major, minor, dorian, mixolydian, lydian, phrygian, locrian, blues, pentatonic) and toggle between chord inversions, dominant chords, and tritone substitutions. Play chords through three built-in instruments (sampled piano, FM synth, plucked synth) with an optional arpeggiator that supports five patterns (up, down, up-down, down-up, chord) at adjustable rates. Build a chord progression on the piano roll timeline by pressing Enter after playing a chord. Resize, move, and reorder chords directly on the timeline. Export your finished progression as a standard MIDI file. The full state is encoded in the URL, so you can share or bookmark any progression.
TonniTools is built to run locally in your browser. Since no data ever leaves your device, everything works, even without internet.