Saturday Night Live's 40-year anniversary opened with a band on Sunday night. Two of the SNL's best and brightest to be on the show over the years, Jimmy Fallon and Justin Timberlake kicked off the show in phenomenal style. Fallon and Timberlake kicked off the show with a version of the 'History of Rap' by paying homage to the show's most famous sketches.

Rachel Dratch and Molly Shannon both made surprise appearances during the skit, reprising their roles as Debbie Downer and Mary Katherine Gallagher to be part of the segment.

As Fallon and Timberlake wound the skit down, they got the show formally underway with that famous announcement "Live from New York, it's Saturday Night!"

See the segment below.