Quote Originally Posted by eyes without a face
these "live pa's" people are knocking out are not Live sets, they are simply a mixture of their own tracks that they've mixed in Ableton, and half the time with no real flow or dexterity to the sets or music.... there are however some who do it extremely well with alot of interactions, fresh elements dropped in along the way etc etc, but its still not live in the sense of playing the instruments, playing the sampler, playing the keyboard, playing the drum machine
If they've got Ableton 4 (or later) then you can use a VST drum machine / synth / sampler etc. - and mix in whole tracks of audio too, e.g. acapellas, atmospheres and so on.

How is this different from using an actual drum machine / synth / sampler?

You still program patterns and trigger them in sequence, doing controller stuff over the top. I don't see how you can say one is any less or more live than the other.