"Live" dance music... What exactly is happening?

Say I went to see Fat Boy Slim live, or Orbital, or The Chemical Brothers. What do they mean by “Live”? It seems to me that all they do is play records. One time, on tv, I watched the Chemical Brothers perfom, studying them to see what the hell was going on. Both guys were in a booth, hunched over a vast array of dials and knobs, tweaking and fine tuning. It looked like a lot of effort was going into this. Then, as the music built to a crescendo, they both lept into the air, delighted, doing the classic DJ “point in the air with both hands” routine. The crowd did the Ruaile. I was more perplexed than ever.

Just what is going on? Surely there must be more to it then pointing and clicking on an audio file and tweaking the sound. Anyone?

Really good DJ’s of this sort “play” their equipment like an instrument. It may not be great visually (without nifty lighting effects, whihch is often part of the set-up) but it’s definitely not just spinning a record. Usually there is a delay in what they hear in their headphones and what played on the speakers, allowing them to sync things up and otherwise seem psychic.
It’s pretty cool, but it’s not my deal.

I don’t think there’s any delay in what they’re listening to over the headphones. They’re listening to the next track in order to time it right (matching the beats).

There’s a difference between DJing (Fatboy) and performing live (Chemical Brothers…although they’ve done the DJ thing too). Although, with DJs starting to use computers to mix, it’s becoming less black & white. And then there’s the who Tiësto In Concert thing, that was some sort of multimedia extravaganza.

Not sure exactly what the Chemical Brothers are doing. But they’re worth seeing live. They do make the button pushing and knob twirling interesting. Great visuals.

Any advance on knob-twirling?

It all depends on what equipment they’re using; in the Chemical Brothers’ case, they’re notorious for taking lots of keyboards, samplers, etc. out in their live show, so I imagine that they’re doing a lot of playing riffs on keyboards and tweaking the sounds, as well as triggering samples and tweaking those sounds. Last time I read an interview with them ('98 or so), they were using several MPC-3000’s (a hardware sampler/drum machine/sequencer/beat machine) in the live set, which meant that at any given time they could mix between a bunch of different beats, riffs, loops, basslines, sound effects, etc. in addition to playing keyboards over top of that.

Again, as someone else said, DJ sets are completely different; the guy is just playing and mixing records, although the more complicated mixers allow them to add and tweak effects and stuff like that. That said, DJ’ing is a delicate artform that’s quite tough to perfect, and a great DJ is doing as much or more work than a “real” musician.