Know for his emulations of hardware (classical like the MC202 Sequencer and new ones like the M185 Ryk Sequencer or Klee) here’s Defective Records‘ Roland MC4 Hack: Work In Progress which connects to the MC4 Sequencer, which is not known for its easy uncomplicated way of working with it – this one is a MIDI File to MC4 converter of course limited to 4 independent tracks.