Five decades ago, the showrunner Lorne Michaels created Saturday Night Live. In the years that followed, the show significantly altered the landscape of live comedy on television. There’s been a lot of turnover in comic talent and the quality of this era versus that one is hotly debated by fans. Still, in every era S.N.L. has produced timeless sketches, entered jokes and phrases into the lexicon, delivered cutting commentary on the political news of the day, and turned cast members into global celebrities. Because each episode features a musical guest, the show’s history is also tied to music: since 1975, its roster has included Prince, Sinead O’Connor, David Bowie, Taylor Swift, and many, many others. A new documentary directed by Questlove delves into the annals of S.N.L.’s musical artists, from Cher to NSYNC and everything in between. —Jack Sullivan