Apart from the “what modules” question there are some important music theoretical underpinnings to this effort.
2 moving pitched lines (here bass and lead) invokes all the problems of counterpoint. If you’re not already comfortable in this area I recommend Hindemith’s book. Not sure the exact title but you would find it pretty quick. COMC Book II if I recall…
From that, my ultra short counterpoint summary guidelines are: contrary motion sounds best, oblique next. Similar motion is good only in a small set of circumstances, usually over small distances. When both voices move, they usually need to go from consonance to consonance. Dissonances need to be carefully controlled. Beyond that are a lot of details that would basically require to read the Hindemith book and a lot of time at the keyboard hearing counterpoint problems and how to avoid or resolve them.
Practically, for your application:
— control of available notes (Pitch class sets) will be very important so your sequences are limited to tones that will pair well with the other line. I use Intellijel Scales to for this as I can set an arbitrary set of tones and CV switch between those sets.
— control of the motion of the 2 lines relative to each other (so that they are not in similar motion too often)
SO I can recommend you consider some modules including:
— Scales, or something like it, so you have definitive control on what pitches you’re allowing through
— Acid Rain Maestro or something like that. Six channels of time synched CV. Very jam-able. This way you could have for example up CV for one voice and down CV for another voice. Flow those through your quantization. That gives you complementary pitch values with controlled counterpoint! ARM is in your MG rack above, okay, good!
— some playable switching like Acid Rain Switchblade or Verbos Sequencr selector. That way you can have multiple “feeder” sequences and you play them with the switch. Of course the switches can also be CV driven.
— handling trigger/gate needs separately from pitch, or at least thinking of these as independent. You have Merton, that gives you a lot of options. Running your pitch values from independent lanes, and trigger / gate values from other lanes, that gives you huge flexibility.
BTW I didn’t scrutinize your MG draft rack too closely, just wanted to put out some ideas of what I would need if trying to do what you want to do.
I hope at least some of this is helpful. I hope my post does not sound condescending; I’ve struggled with a lot of these topics before and wanted to share a few of the helpful points I’ve learned. I’m interested to hear how this develops for you. I’ve been working on some similar directions and am curious to hear how this develops for you.
Cheers,
Nicholas