Well, if you have legal permission (by license or creator) you may, in the case of binding of Isaac I'm pretty sure it's copywritten but check for some CC0 music in the same style, there's a lot of that on opengameart.org.
Viewing post in can i insert other game's music into my game?
is everything there CC0? i've found some musics that i though it'd fit but it seems to be from a game called "monser 2 rpg"
42 "Monster RPG 2" music tracks | OpenGameArt.org
i looked for it and people have used the musics whitout truble so i don't know