If you use music for which you don’t own the rights as the soundtrack for a video, you’re likely to get flagged as a copyright violator.  YouTube is particularly nasty about this.  Facebook also will threaten to shut down your account if if happens too often.

The following are three sites that come highly recommended by a friend in the music/advertising business.   These stock music libraries allow you to preview royalty free music for download. 

It’s worth spending a few bucks to make sure your sound track doesn’t get your YouTube or other video sharing site shut down.