I would recommend that you check out Bandcamp. There's ton's of independent artists on there that you could get ahold of. Some people even say in their bio that people are free to use their music just as long as you credit them. That depends though, some artists reserve the rights, but you probably have a better shot negotiating rights with indie artists than signed artists. It's not like a creative commons library; you can find any genre under the sun, most of it being decent recording quality. Not to say that there is junk to search through... I mean, there is, not a lot, but there is- you'll find stuff like lofi hiphop and lofi garage rock, which you might not be appealing unless that's the sound your going for.
