Music with code

hi there, i am looking to use a fair amount of music in a project that a user has dynamic control over. because file size is an issue i was wondering the best way in which to optimise file size and performance? i have noticed the loadSound command for retrieving it from a server and also considered using a linkage and not exporting in the first frame (if i do this how do i export it afterwards?). any help would be much appreciated.