IS the music copyright?

I've always liked to listen to wynncraft music when I go to sleep, I'm currently working on a game with some friends, it's also a mmorpg (it's on Roblox, I wanted it on Minecraft but my freind doesn't have a Minecraft account) I wonder if I can use wynncraft music? A lot of people say it's non copyright, but I kind've would feel bad if I don't ask in the forum about it. So is the music copyrighted and can I use it in games?