When Taylor Swift wrapped her Speak Now tour here in the States last November, many worried about which current star would be able to carry the burden of performing a surprise song by another artist during their live act. Even if you have a hit album, audiences still want proof you can carry a few bars of "Mele Kalikimaka" or "The Humpty Dance," if only to justify the steep ticket prices. As Taylor has resigned herself to Hunger Games and working on limiting her surprised face to truly phenomenal occurrences, her prestigious cover baton has been passed to Kelly Clarkson, who's incorporated similar moments of flattery into her Stronger tour. Simon's first American Idol covered the woman Simon could potentially hire for $10-20 million on Tuesday night, performing "Till The World Ends" by Britney Spears during her gig at L.A.'s Nokia Theater. Production was stripped down when compared to the original, with Clarkson popping a squat on a high chair as her band members gathered behind her. Dancing in one's seat is totally acceptable when able to give one of our favorite songs of 2011 tons more vocal depth and grit in three breezy minutes—plus, it's the only way we know how to groove. Watch below.