an interesting point.
but copyright protects expression, which probably means putting a sequence of notes together to produce something musical that everyone else recognises as a tune.

you could argue that the best performers are selected for sample sessions because their playing expression is superior to more average players.

I have not heard of Akai or Korg taking someone to court over stealing of samples, but I think you would have to re-sell the samples as your own to break the law?

Has there not been a precedent set over the legality of sampling musical phrases from other recordings and stringing them together to a new beat?