Ok I have all my music on parition /F/ and i want to make it so i can listen to music during games. I know you have to move it to the /E/ partition, but where do u put it in there? UDATA or TDATA or wat?

Its not that simple. The xbox makes it like a gamesave, making it not just like all your mp3's. It has to convert them, etc.

so no music when playing forza

1- the xbox soundtrack is located in E:\TDATA\fffe0000\music\
2- you cannot just copy your WMA files there and expect them to work. The database file (ST.DB) needs to be edited as well. This whole process is simplified by using an app called VXCR (Virtual Xbox CD Ripper...search for it).
3- you can only use soundtracks in games that support them (luckily, Forza Motorsport does)