NBCUniversal Inc. September 21, 2019 4:31 am 'Tonight': Chrissy Metz and Jimmy Fallon Improvise a ‘This Is Us' Theme Song “This Is Us” Actress Chrissy Metz give hints about director M. Night Shyamalan’s cameo in season 4 and improvises a theme song for the show with host Jimmy Fallon. US & World Videos 2:31 Celtics preparing for pivotal Game 3 against Heat in Miami 1:17 Patriots player visits Franciscan Children's Hospital 5:54 Pro-Palestinian protest taking over college campuses 2:47 AI pharmacist? Brigham testing new tech to assist docs, pharmacists 1:39 Patriots superfan slams Tom Brady's ‘crap autograph'