Here is a nice talk by Mark Ronson that covers the history of sampling and how it has influenced modern music. This reminds me a lot of the ideas that Paul D Miller aka DJ Spooky was talking about several years ago.
Here are a couple of the talks he mentions near the beginning of the talk:
I’ll definitely watch this later but I have a bone to pick with Ronson… I saw him at a festival and it was obvious he was ‘playing’ off one track. Anybody else seen this or was this an isolated thing?