Off-Topic

I realize that this might be a bit more off-topic for this site than other posts, but I was listening to Justice's live album "A Cross the Universe" along with Daft Punk's "Alive", and I was wondering, what exactly are the guys doing on stage to play the music? Given the nature of the genre, they could technically just press play on a machine and just fake everything else, but I really doubt this is what they do. Do they just start certain loops of a song and just add and remove other loops as they go? Do they actually rhythmically hit a button over and over again to make a beat? I would love some clarification on this as its been nagging at me for a while.

They mix and match their samples to a ridiculous extent to control the crowd. That's why the live album is so insanely different to the studio albums.

Depends. This is a good introduction to a more or less loop based approach:

GusGus prefer twiddling knobs on their massive modular synths:

Or you could do it (almost) acoustically:

I actually think they mostly fake it. Whenever I see a live video of Skrillex for example he's just twisting knobs and jumping around. I don't really think it matters though because the people going to these concerts aren't there to see someone perform for real. They're there to hear it live and see the person who performs it. Daft Punk performances also seems more like a lightshow than a concert to me.

A lot of them like Haduken use live instruments from rock groups to balance it out

Daft Punk use these tablet computes called sequencers built into the pyramid; they put together the various samples of music they created and put the whole song together live.

I assume they're basically DJing and mixing all their material together in new ways.

I know the Gorillaz and Dethklok just rear project their cartoon imagery on a giant screen over the actual members of the band playing their instruments.