In general I believe this to be the case so long as you give the right credits etc. BUT you may fine each individual may have certain stipulations of use so you would have to check with the original authors of the music to see it any restrictions apply. Sorry if that's not as black and white as you would have wanted but the law isn't alway black and white.
I'm not a legal expert I'm just going off my understanding of what I've read on the internet. Have you had a look at Creative Commons