RHUL has it's own converted house dedicated to music. It's also got its own library, and whilst it may have a good reputation, the feedback from the course is much to be desired. There aren't very many practice rooms, either. Have a look in the RHUL forum on here for more about the music department.
Languages at RHUL are highly recommended though.
Even though there's not much to do in Egham, it does actually help out financially. Some of the more social halls mean you don't have to go out to have fun (ie, Founders) and there's always nearby Windsor to go to for nightlife. London isn't that far away, but getting back may prove to be difficult.