Hello. I had an epiphany last evening, when I took the QuNexus and the XKey to the PC laptop, so I could play with all the (400?) instruments that came with the Roli LumiKeys, but which I can’t access on the iPad since the Roli Studio only works on PCs and “real” Macs. I have a rock-bottom HP laptop, with only 2 USB ports, so I used a generic USP splitter and both intruments plugged in. I had the XKey above (further from me) and the QuNexus nearer, and had never tried to play any combinations like that physical arrangement before. My guess is it’s similar to some sort of two-tiered organ arrangement, maybe? Anyway, the XKey is easy to play, and full piano sized keys, but only polyphonic aftertouch and velocity; not MPE.
The QuNexus, with its cool squishy keys, is very expressive. So here’s the discovery: I can play the piano keys with mostly fingers, and still a counter or bass with mostly thumbs, and can “dig in” with the squishy MPE buttons. I set one keyboard an octave or two from the other. No doubt old hat to most of you, but a bold discovery for a rookie like me! Now, I need to try the setup with the other 2 MPE controllers I have, and the iPad, so I can mix as above but with two completely different instruments! More fun!
And, does anyone know a cheap or free software mixer for the PC, so I might use different instruments there, as I do with the iPad and AUM? Or, perhaps I can just open two copies of Roli Studio Player and link each to a different controller? Any advice will be appreciated, as always.
Roli Studio is afaik available as a VST plugin. So the easiest way to run several instances with different sounds in parallel and to route one midi controllre into one and another midi controller into the other instance would be a VST host - or if you also plan to record at some point a DAW.
There are MANY options. Here a few proposals to look into.
My personal shortlist would be:
- Usine Hollyhock Free (+good modular host with a usable free version +powerful -complex)
- GigPerformer (+very good live host +great balance between simplicity and power -$170 -not optimal for recording).
- Bitwig Essentials or Live Lite (+good multi-expression-note editing capabilities, a good solution when recording and manipulating MPE midi data +/-:$79/$99 for the Lite/Essentials versions of Bitwig or Live -“the Grid” or “Max for Live”, great modular systems are only available in the $400/$500 Studio/full version of Bitwig or Live)
P.S.: Removed Cakewalk from the personal shortlist for this scenario - working with MPE data is too cumbersome imho. One would have to record into 16 midi tracks, one for each channel. Otherwise it’s a great DAW though.
P.P.S.: Also took off VCV Rack from the recommendations list for this project. Just did some experiments, at least I don’t get the Host to react to MPE messages correctly. This is surprising as all the synthesis components supports polyphonic signals and there is an MPE capable MIDI-in module. Theoretically one can get MPE to work by having several Host modules, one per voice - but that isn’t optimal.
P.P.P.S.: I just saw that I still have a free code for Bitwig 8 track (a version of Bitwig that is limited to 8 parallel tracks - which should be plenty for your use case). If you want that send me a PM, then I can give you the code.
Wow…Thanks, NothanUmber, for a thoughtful and (looks to me) a comprehensive list for starters. I am most interested in “free” software so I can try more controllers (!) I will PM you, as you suggest. And, I’ll look into Usine Hollyhock Free, as well.
Have fun! 
One host to keep on the radar would be Element: Element - Kushview
This is an open source live host and works as standalone or as plugin itself.
Currently I still had some issues running SurgeXT in it, but it is under constant development, thus looking very promising!
P.S.: Just tried it with Roli Studio, there Element doesn’t crash - seems to be a problem specific to SurgeXT. So it might be worth a try already.
P.P.S.: Seems to be a combination of ASIO4All and SurgeXT that it doesn’t like. When either switching to another synth or switching to Windows Audio low latency mode instead of ASIO it works.
P.P.S.: The downloadable binary 0.49 version has various bugs that seem to be fixed in the current version (like pitch bends not being sent to vst3 plugins). These newer versions are currently only distributed to Patreon supporters - or one has to build them oneself from the sources. Next public release will be 1.0.