Is there a plugin that generates multiple variations of a melodic sequence in MIDI?

Making Psytrance.

 

If you mean something like a calculator/generator, there is Notewarp. https://notewarp.de/
Midi Agent, which is AI: https://60minuteapps.com/tool/midi-agent

But if you are looking for probabilistic sequencers, those are a different kind of software.

 

Plugins
https://www.musicdevelopments.com/melodya.html
https://www.musicdevelopments.com/midimutator.html
Standalone (includes functionality of both of the plugins):
https://www.musicdevelopments.com/index.html

 

Last edited: Apr 2, 2026 at 10:19 AM

If you use Ableton Suite, there are a ton of those in the Midi Tools (the one that you use inside the clip) as well as many M4L devices.

For plugins Scaler 3 (or 2) can do this, and Audiomodern Riffer comes to mind as well. Riffer is actually really good for this. Just lock some notes or params and have at it. It will even auto-generate new variations every "X". There are others, but those quickly come to mind.

 

510K Seqund does probability with a parameter they call "Chance", which is great but it only determines which of the pitches in 2 lanes get played. But by locking in a scale or customer keys, every randomization will adhere to those notes only. You can have multiple patterns in it with variations, or you can use just one and drag the midi file out. It's built around rhythm more than being all piano roll first or like Scaler.

ADSR has Hexcel and MidiGrid which are both MFX plugins that can easily randomize anything. But these plugins really do not just crank out midi files.

 

Thanks so much for the useful tips. Much appreciated everyone.