So, there is a guy who is creating commercials for youtube.. advertisements for his business. He's presented me with an audio track of about one minute that is copywritten, and wants me to write a piece of about the same length that's very similar, but not similar enough that he'd be infringing on copyright. He'll pay me $500 for the track I produce, and he says there's no reason for me to be credited in the youtube video or the description, and that I can't sell this track to anybody else, and that basically I'm out of the picture after I get my $500. Though he did say that if someone asks him about the music, of course he'd tell them who wrote it, and not pretend it was him. Are these terms fair for a scenario like this? Basically where he's coming from is that he invented the "patent" and I'm basically just a worker working within that patent, because I would have never, ever thought of creating this thing on my own.. it's not really my invention. I'm just an executor of a task within his architecture. I feel this is probably okay, because I mean, in commercials on TV you don't see who the composer of the music is, you don't see the composers in movie trailers (i.e. immediate music).. so it makes sense to me that in a scenario like this, I do the work, I get paid, and then it's pretty much his property. Is this fair? Or is he tricking me?