There's nothing prohibiting it, as long as it's not by one of the composers in the music that may NOT be posted for legal reasons (
Thread 49829) thread. Do you want to post info about it or actual download links? If the latter, just find the appropriate sub-forum (VGM, classical/soundtrack, anime, etc.). There are a couple of unreleased soundtracks that I'd like to post, but I've been too lazy to prepare them LoL!