I mean, I understand basically how sampling works. Here’s what I’m unclear on:
There’s a hip hop song. It’s got a beat (sampled or created, doesn’t matter) and then they have, say, the bassline from “Play That Funky Music” or a guitar part from “Kiss” laid over it. How do they get just the bassline/guitar part on there, without all the rest of the instruments on the original song? Do they somehow get the master tapes? Or is there a way to isolate a single instrument and suppress the others with samplers? Is that clear?
for official remixes, yes…from one label artist to another. They’re not generally available to the public but are occasionally leaked, intentionally or no.
There are some isolation techniques, but depending on the instrument or part, they have varying success. Most samples of instrumental parts are pulled from breaks or instr sections.
There are also sites available for grabbing parts legally, such as ccmixter.com. They range widely in quality.
I will usually recreate a part if needed. Depending on the profile of the project, I might recreate verbatim or alter sufficiently to muddy the waters of copyright.
My understanding is indeed that one needs access to the master track to isolate tracks effectively. I used to do good bit of sampling in my 20s on an E-MU rackmount sampler, and then moved on to fool around with software-based sampling/looping/audio editing applications and, so far as I know, there was no good way to isolate tracks from a final mix.
I mean, yes, there were certain tricks you could do to remove the vocals. Since vocals were usually dead center in the mix, and everything else was usually panned at least slightly towards one direction, you were able to exploit this by basically flipping one of the stereo channels, and combining them into mono, so everything dead center gets cancelled out. It was hardly a perfect solution, though, and there was usually at least a little ghost of the vocals still left in the mix.
When I went through my sampling phase, since I didn’t have access to master tapes, what I would normally do is listen to music and watch out for instrumental breaks that would work in a sampled context. If you listen to a lot of sampled music, especially from the 80s, you’ll find this is exactly what was done. No need for master tracks or studio trickery, you could often find what you need on the final mix. Take Vanilla Ice’s “Ice Ice Baby”. That’s an easy one, “Under Pressure” starts with an unaccompanied bass riff. “Play that Funky Music” starts with a solo guitar that easily loopable. Or take Ton-Loc’s “Funky Cold Medina” since you mention Kiss. That guitar riff is from the intro to Kiss’s “Christine Sixteen,” in a guitar-only break.
If the song is for commercial release, they’re going to have to clear it with the copyright owner anyway. So it makes sense to ring them up early in the process and see if they’ll make the multi-track files available.