Dancing With the Stars is celebrate it’s 20th anniversary!

The ABC dancing competition threw the “ 20th Birthday Party ” for the quarterfinals on Tuesday night’s (November 11) episode, with past pros, winners and even former host Tom Bergeron returning as a guest judge.

Derek Hough choreographed the opening routine, which featured season one pros Alec Mazo , Ashly DelGrosso , Louis van Amstel , Jonathan Roberts , Charlotte Jorgensen and Edyta Śliwińska dancing along the current pros and troupe.

This week featured two rounds of competition, with each remaining couple taking inspiration from an iconic past freestyle and in round two, the seven celebrities danced without their pro partners for the Relay Dance competition, being paired with past winners.

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