What licenses are allowed into repositories?

[Ubuntiac]

Hi there,

I'm working on a game with GPLv3 code and have the opportunity to use some CC BY-SA licensed music. Would including this exclude my game from the Ubuntu repo's?

I read somewhere that the music might need to go into Universe repos. If so, could I have the game in a GPL package in standard repos, with the music in a game-music package in universe?

Thanks in advance for any ideas/opinions/pointers to info elsewhere!