— Free tool
Melody & Bass Generator
Bring a chord progression — from the Chord Progression Generator or typed straight in — pick a style, and hear a topline and bassline that know the harmony. Reroll the rhythm and the melodic contour holds; reroll the pitches and the groove stays put. Then export the multi-track MIDI, send a line to the Synthesiser, or share the exact take as a link.
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— FAQ
How does it know which notes fit the chords?
Every chord in your progression is analysed before a single note is placed: the generator derives its chord tones, a compatible scale (a ii7 in a major key reads as Dorian, a secondary dominant as Mixolydian, borrowed chords get the mode that actually contains them), and approach notes into the next chord. Strong beats draw from chord tones, weaker beats from the scale, and chromatic notes are only allowed as passing figures that resolve by a semitone. The piano roll shows all of this — amber-solid notes land on the harmony, faded ones add scale colour, pink ones are chromatic passes — so you can see why the line works, not just hear it.
What do the reroll buttons actually keep?
The generator runs on independent seeded streams for rhythm and pitch, per part. “Reroll rhythm, keep pitches” draws a new rhythm while the melodic contour — the motif and its transformations — stays put, so the line changes shape but keeps its identity. “Reroll pitches, keep rhythm” is exact in the other direction: every onset and duration stays precisely where it was while the notes move. “Melody only” and “bass only” re-throw one part and leave the other untouched. The seed is visible and editable, so any result can be typed back in and reproduced.
Can I use the melodies commercially?
Yes. Everything this tool generates is yours to use in any context, commercial or otherwise, with no attribution required. Unlike chord progressions, melodies can carry copyright — which is exactly why the tool generates yours from your seed and your settings rather than serving loops from a pack: the output is a starting point that belongs to your session, not a sample cleared a thousand times before.
How does the MIDI export work in my DAW?
The export is a Standard MIDI File (Type 1, 480 PPQ) with separately named Melody, Bass and Chords tracks, the tempo you set, and a key signature — so it drops onto an Ableton Live, Logic, FL Studio, Cubase or Reaper timeline at the right speed with each part on its own track. The loop-count option writes the whole progression repeated back to back, and you can also export the melody or bassline alone as single-track files. What downloads is exactly what you auditioned, swing and dynamics included.
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