Originally Posted by DrumEatDrum
And no, you can't claim any copyright on drum parts. There was a thread on this topic recently, but for the most part, copywrites cover lyrics, melody and harmony, but not drums. And if drums could be copywritten, everyone here would be in massive financial debt to Cozy Cole, Gene Krupa, Ringo Star, et all, for playing beats and fills that have been played by someone before.
I don't think the issue here is one of copyrighting a specific part - the royalty issue is to do with writing credit, which would normally be decided before release. In a fair world, you'd be given a percentage of the writing credit for each track depending on your contribution. You should also be given a portion of the mechanical royalty for each sale even without writing credit.
That said, unless this group are going to be selling hundreds of thousands of records it's best chalked up to experience.