Covers are a tricky business. Any time a musician starts trying to do his or her own version of someone else's song, they instantly take on some pretty hefty expectations. First, they have to satisfy their own fanbase, which may not like the artist being covered to begin with. Then they may even want to satisfy fans of the original artist (or the original artist themselves), which is even more difficult because no fan of an original is ever satisfied with a remake. It's nerd law.
But kudos to those intrepid artists who not only attempt covers, but go well outside of their own genre and take on unexpected and hallowed, untouchable classics to cover. Those who try that have some serious balls, or really don't care what critics think, because they mostly always fail.
Oddly enough, these five did just that and managed to actually succeed, beating million-to-one odds of these covers being absolutely horrible.