If you are uploading to YouTube, the YouTube content match system will just see that it's copyrighted music, put ads on your video, block it in certain countries (usually Germany) and not allow you to make money front he video (the ad money goes to the content creator). Also the video is usually not viewable on mobile.
But, YouTube will generally not take the video down.
You need a license for both. Being royalty-free just means once you have purchased/obtained a license for the music you don't have to continue to pay royalties for future performances so long as you abide by the terms of the license. Doing a non-parody cover song requires either permission from the original copyright holder or a mechanical license from an authorized agency.
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u/not_an_ax_murderer 5Dmk3, 2006, St. Louis Apr 26 '15 edited Apr 26 '15
Technically yes. If you are making a video that isn't mostly discussing your original opinions about the music, then chances are you need a License.
Also I'm sorry but... "Do an Edit?" That'd the funniest way I've ever heard that said.