Tina Fey Justin Bieber SNL16-year-old pop singer Justin Bieber visited 'SNL' on Saturday as the musical guest. He sang 'Baby' and 'U Smile,' with backup dancers who seemed to not tone down their dance routine to fit the small stage they were given. Host Tina Fey described the young singer as a boy whose "smile is like watching a baby bunny sniff a tiny flower." Bieber even tried his hand at comedy in a sketch about a teacher, played by Fey, with a crush on a super-cute student. Watch: