Lady Gaga will honor her friend and collaborator Tony Bennett at a concert celebrating the jazz legend's 90th birthday. The two-hour show will air on December 20th on NBC, the network announced Tuesday. Other performers include Aretha Franklin, Andrea Bocelli, Billy Joel, Elton John, Michael Bublé, Diana Krall, Rufus Wainwright, k.d. lang, and Stevie Wonder. Gaga and Bennett first collaborated in 2011 on his Grammy-winning album Duets II, on which Gaga sang "The Lady Is A Tramp." Three year