Last night on Late Show with David Letterman, Justin Timberlake bursts into song — first about what Letterman’s drinking out of his coffee mug and then about a scene from In Time — all with the express purpose of demonstrating why musicals are so weird. Plus: Elizabeth Olsen, on her first-ever appearance on a late-night show, channels her study-abroad semester in Russia to tell Jimmy Fallon “good-bye†in five languages; Andy Richter scared Jane Lynch out of the closet during their filming of The Real Live Brady Bunch; and Salma Hayek teaches skin-rejuvenating face exercises. Watch our compilation to see what you missed.