Alternative

[rain91]

So while I was at work i got a text from my brother asking me if i wanted to dj for his birthday. First thing that came to mind was uh, sure. Thing is he doesn't really seem to be into dance music in general. Hes a car guy and for as long as i can remember hes been into alternative rock music, and a good portion of his buddies are car guys too who also like that type of music. It seems a pretty chillax kinda thing but im not too sure what to play. Suggestions? Questions?

[lethal_pizzle]

...this is just the generic

I play x. Someone wants me to play something != x. I don't play != x. What should I play?

question. I shall give it my generic answer:

If they want you to play the music you own and play; then play.
If they want you to play music you don't own or play; then don't play.

Although it seems to me that you've agreed to something, but you're not sure what. You'll have to talk to your brother, to find out what your brief is.