Alexa PenaVega & Mark - Foxtrot in Season 21 of Dancing with the Stars(DWTS) Week 4 on Oct 5th, 2015. Week 4: Most Memorable Year Couples performed one unlearned dance to celebrate the most memorable year of their lives. For the first time in the history of the program, Tom Bergeron did not preside as the episode's host; he was absent to be with his ailing father. Alfonso Ribeiro filled in as host in Bergeron's absence The couples dance the cha-cha-cha, foxtrot, jive, quickstep or salsa. Bindi Irwin & Derek Alexa PenaVega & Mark Gary Busey & Anna Tamar Braxton & Val Nick Carter & Sharna Paula Deen & Louis Victor Espinoza & Karina Andy Grammer & Allison Hayes Grier & Emma Bindi Irwin & Derek Chaka Khan & Keo Carlos PenaVega & Witney Alek Skarlatos & Lindsay Kim Zolciak & Tony
