Questlove's "Ladies & Gentlemen... 50 Years of SNL Music Documentary" will look back at the show's 900-plus musical guests.

NBC continues to celebrate the 50th anniversary of "Saturday Night Live" with the new documentary, "Ladies & Gentlemen ... 50 ...

Ladies & Gentlemen… 50 Years of SNL Music' premieres on Monday, Jan. 27: Here's where to find and watch the TV special online for free.