i posted this in the Q&A/tips & tricks forum, and got a couple of replies, but i thought i'd try reposting it here to a larger audience.
so here it is:
i've been trying to figure out how to use REAPER for live loop-based performance. i'd like to be able to do something like this:
https://www.youtube.com/watch?v=gRRpLjEaqxs
he's using an MPC in track mute mode, which, as you can see from this video:
https://www.youtube.com/watch?v=I53UO-K6ViE
...won't turn the loops on or off right when you hit the button, but at the next loop point. which makes sense when you're watching damu's fingers in the first video, because he's always hitting the buttons before the beat, basically telling the machine "turn this loop on/off at the next loop point."
so, i've been trying to figure out a way to use REAPER in this way, controlling it with my (soon to arrive in the mail) korg padkontrol.
so far i've come up with an (admittedly inelegant) solution. my idea is this (i'll track it backwards from the sound to the controller):
1) create a track in reaper and place shortcircuit in it as a VST. this will be my audio output track. optionally, set the audio output of shortcircuit to a series of tracks if i want realtime FX on them.
2) load my loops into shortcircuit so that each one has a unique MIDI note assigned to it. set them up as one-shots (so, not loops at all really).
3) for every track i want to be muting/unmuting, set up a track on reaper that consists only of a short MIDI note at the beginning of every loop to trigger shortcircuit. so they're not actually looping, just getting constantly re-triggered by these MIDI notes. if my longest sound is four bars long, i'd only have one MIDI note at the beginning of that track; if there's e.g. a drum loop that's only one bar long playing simultaneously, i'd have to have a MIDI note at the beginning of every bar.
4) highlight the (four-bar in this case) MIDI sequence in REAPER, and set playback to loop.
5) assign a different set of MIDI notes (or if possible CC messages -- because apparently those stay lit on the padkontrol?) from the padkontrol to mute/unmute REAPER's MIDI tracks, thus, turning on/off the MIDI notes that are triggering shortcircuit *without affecting the audio tracks themselves*.
6) mute all tracks except those representing loops i want playing from the beginning of the song.
7) press play.
thus, when the MIDI tracks are muted in the middle of a performance, all that is in fact muted is the signal to shortcircuit to play the loop again, so it'll play to the end but then not play it again. likewise, if the track is unmuted, it won't start playing the audio until it reaches the next MIDI note.
the downsides to all this are:
1) it's kind of cumbersome, but much more importantly:
2) there's very little in the way of visual feedback. by having the large mixer at the bottom of the screen i can see the mute buttons and whether they're lit or not, and i can also map my padkontrol so that buttons 1-16 will control tracks 1-16, but i wish there was something more intuitive than that. the MPCs only have that crappy little LED screen but at least in track mute mode its display is intuitive: it's arranged in a 4x4 square (just like the buttons, unlike in reaper where it'd just be a row along the bottom of the screen), with each square having a short name, and the whole square being lit or darkened according to whether it's muted or not.
does anybody have any more elegant solutions (other than "switch to ableton")?
could i maybe use seq24 for this task?
it definitely has the perfect visual interface that i'm looking for, but in my playing around with it i haven't found a way to:
a) route the MIDI output of seq24 into REAPER in order to trigger the sampler, or
b) assign MIDI signals from my padkontrol to mute/unmute the different MIDI tracks.