I think back from the last 10 years. Seems like every single mainstream horror film of the last 10 years just about has a rapper or singer in it. Freddy vs Jason H20 Halloween:Ressurection Seed of Chucky Resident Evil 2 (Was the black guy some kind of singer? Could be wrong here.) are just some examples. Studios think they are some major selling point. Why? People did not go to see FVJ for Kelly Rowland for example. They went to see Freddy and Jason. The movie would have made what it did regardless if she was in it or not. Same with the last two halloween films. I mean sure, a rapper might bring maybe 1% of the audience, but in general the idea of it is laughed at anyways. So, will studios ever realize that Rappers and Singers in horror movies arent what makes them successful? 9 times out of 10, they are horrible and just distract even further from the films. One exception might be Seed of Chucky where a famous girl singer serves the purpose to be their in a guest cameo which points fun at it. But, thats all I can think of.