Rurouni Kenshin: Meiji Kenkaku Romantan Saisen

So I know that there is a 'library' for tons of BGMs...
But,
when you fight, there's just only one BGM that plays over and over...
I wanna listen to real OST of Kenshin while controlling characters..
But is it possible to choose which BGM to turn on and off?
Or am I just stuck with only one BGM while fighting with characters??
I would appreciate some answers Thank u guys!