electric_diver
Contributor
Royalty Free doesn't mean you are licensed to use the music for whatever you want. If you are going to monetize your videos you want to be very careful. I've used many songs from incompetech.com/ Kevin Macleod at incompetech allows you to use all his songs on monetized videos, you just need to provide attribution (credit) on the video.
I've used Kevin Macleod work in all my videos on You tube. All you have to do is properly attribute it when you use the creative commons licensing option. He even provides a page that will fill out the required text for you.
An example of the required attribution:
"Piano Between"
Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0
Creative Commons — Attribution 3.0 Unported — CC BY 3.0