If they have the appropriate audio interface, they can have a lot of control over there tracks.
There are a lot of different branches of 'playing live' with Ableton.
There is Scene and clip launching. Sometimes that alone can be insane, if you have an elaborate enough set. They may do that while playing an instrument. Or adjust some things while launching clips. In this case though, a lot of the clips are there at their disposal before they walk into the club.
There is mixing/fx/tweaking. You can adjust things on one or two channels, or on 16 channels. Or 8 channels and five Return channels. These channels can sometimes help to have EQing done using a mixer, if each of them is sent to a channel on the mixer instead of going out to the master. The odd thing about using a mixer in this way though, is that Return channels still get the original audio. It works great though for people who use all their effects self-contained in each track. Of course this can be combined with the Scene and Clip launching
Or it can be done with your set being laid out in Arrangement View. A lot of focus sometimes has to be put on alllllll that fn tweaking though!
Playing instruments. You can play beats/keys/guitar/vocals/etc. etc. and do many kinds of layering and looping. Sometimes they will start with very little material and build it up. Other times they may have a number of backing tracks, and get things going. With their hands pre-occupied on instruments.. it takes away from their ability to tinker with effects (feet, use extra hand, have your buddy play with the fx!), but people are still able to make brilliant use of this style of performance!
Something else of interest, for performing live in ANY Kind of situation, is How they intend to play songs.. as in, do they follow a rigid structure Every single time they play? Or do they leave room for improvisation? Would you feel more let down with one method or another? Sometimes, it takes much focus to stay strictly on the path that the song was intended, it takes restraint, yet masterful control to mimic it perfectly every time (unless of course you are just launching clip 1, then clip 2, then clip 3, take a bow hahaha). As for improvisation, you have the chance to interact a lot with the vibe and the crowd. Or you give yourself a chance to come up with new ideas on the fly..
Each of those two methods do rely on whether or not you have other people playing with you, the style you play, and what each of their abilities/intentions are.
Yeah.. so what are they doing??? Does it sound good? haha. If someone fucks up bigtime at a show you are watching, give them a nice triumphant cheer for me. Screwing up takes class
