Mash-ups -- remixed tracks that combine two or more different songs into a brand-new unified whole -- offer exciting new perspectives on your favorite artists by showing how much they have in common with the work of other musicians.

Together with Diffuser.fm and Loudwire, we've prepared a list of 15 of the very best mash-ups the internet has to offer, featuring sometimes inspiring, sometimes amusing but almost always surprising appearances from Led Zeppelin, Black Sabbath, Ted Nugent, and yes, even Mr. Rogers. So enjoy our list of 15 Mash-Ups You Need to Hear: