Will Patti Smith cover Nirvana at FreeFest on Saturday? (Jason Kempin/Getty Images)

TV on the Radio, "Waiting Room"

When footage of this cover from July's Pitchfork Festival surfaced on the internet, we were thrilled to finally hear "Waiting Room" being performed by a band that seemed to have an understanding Fugazi's sense of tension and release. If TVOTR don't play it on Saturday, we're demanding our zero dollars back.

Cee Lo Green, "No One's Gonna Love You"

Did Cee Lo make us actually like a Band of Horses song by turning it into a diet-trip-hop-pseudo-soul-power-ballad?

Grace Potter and the Nocturnals, "Cortez the Killer"

Potter and her crew are known to cover classic rock hits by the bushel, but their take on Neil Young's "Cortez the Killer' might be the heaviest.

The Black Keys, "Grown So Ugly"

Another band that isn't shy to cover its influences. The Keys have covered oodles of blues, soul and classic rock tunes, but we'll go with this take on Captain Beefheart and his Magic Band. Shout to Jon Huntsman.

Patti Smith, "Smells Like Teen Spirit"

This might be one of the most courageous covers floating around out there — a shambolic rendition from a rock legend who isn't afraid to add a few extra syllables to one of the most iconic rock songs of all time.