Not really sure how to go about this as I've never had to before. I was wondering if Prodigy had purchased the rights to the vocal in Voodoo people or if sampling them yourself just like they did back in the day is still fair game?
"The voodoo, who do, what you don't dare to people." is what i'm interested in. [Only registered and activated users can see links. Click here to register]
Sampling was included in the copyrights act in 1988, caused bit of a stir previously. So it's likely that the Prodigy or XL Recordings will have paid for use. After generating so much publicity and cash, there's really no other way than to pay or end up in court and pay more.
If you're not making money from the track then you don't need to worry..
As for your specific example, I can't imagine the Last Poets would be too happy if they weren't compensated. Purchasing is not the right word. The sample is licensed. There have been some cases where artists haven't cleared the use of their sampled work. Prodigy's "Smack my bitch up" is an example of this. Sheila Chandra would not license her original vocal, so they had to go into the studio with another vocalist and re-record it.
Even though re-recording something may avoid having to license the sample, a publishing royalty may still need to be paid for the original composition. However, it could also be classed as a derivative work, like Stairway to Heaven is a derivative work. In the case of derivative works, there are no royalties. So even though Led Zeppelin didn't compose the leading passages that form the basis of the composition, in the context of the work in its entirety, their use of these parts constitutes something that is distinct and separate from the copied work.
Currently, a trust representing Spirit is planning to sue the Zep, but it probably won't stand up in court under a musical analysis. But who knows. If you listen to the original composition, sections of the guitar performance are similar and the movement of the strings is represented in Zep's version. Listening to Jimmy page's performance on the other hand, you can clearly hear how he has derived inspiration from the themes of Taurus and then expanded upon them. Stairway also incorporates some upper harmonies into the arpeggio making it a more technical piece to play. But if you remove the harmonies it's a rather simple progression in A minor which would probably be underlying a number of compositions.
So again, if you look at the composition as a whole the comparison between the two breaks down. Musically, they are vastly different pieces, especially considering Stairway's five times the length and covers a whole lot more ground.
Should Spirit get a royalty? Maybe. I think at this point, the guys can afford to cut them in on the deal. If I was Jimmy Page, I'd give them five per cent on future re-issues and a nice fat advance. But hey, maybe that's why I'm not Jimmy Page.