I think there should be a Jukebox to listen to the game music.
It can be an item that you can buy, equip and have your favorite music play no matter where you are.
Or it can even be a NPC stand where you can listen to the music from the person.
Or last resort, they release a DLC Soundtrack, like Binding of Issac did on Steam.
The music in spiral Knights are great and I would love to hear it more when I'm not fighting for my life.
Itunes.