think aphex twin is a really interesting example of a musician. think the whole genius/savant thing is overblown, but he is obviously very good at playing with and programing gear to get silly, weird sounds and the squeezing them into little techno/ambient/break tracks. he also clearly spends a lot of time fucking around with soft and hardware. I'd be really really surprised if much of his stuff is samples, as was said up thread, lots of his stuff is player piano, like avril 14 (which iirc was designed to sound playable but actually impossible for one person to pay because of the double octave stretches?).
a lot of the daw attempts to recreate aphex twin dont quite hit the mark for me, often they sound too polished or too intentionally broken and I think thats cos rdj spends a lot of time fine tuning the velocity of his drums in particular. I wouldn't be surprised if he's more recently moved onto daws but uses things like max//map or the procedurally generates stuff bands like 65daysofstatic are doing on programs like unity.
I used to spend quite a lot of time trying to make tunes which sounded a but like him or venetian snares on ableton but in the end never quite managed to do it and eventually it just wasn't that fun.
