Psi-quencer is a MIDI probabilistic sequencer based on images.
New in version 1.5:
The “Probabilistic Bean” drawing tool has been added.
In edit mode:
-Select control points to move them.
-Double-click on control points to adjust path width.
BEST USED WITH A PRESSURE-SENSITIVE DEVICE!
https://undefinedbehaviour.gumroad.com/l/psiquencer
And a free demo version is available there:
https://undefinedbehaviour.gumroad.com/l/psiquencerdemo