Watch Fallon, Timberlake Channel 40 Years of 'SNL' History

Dynamic duo offer a comprehensive greatest hits primer with a rousing song and dance routine

Justin Timberlake and Jimmy Fallon did what they do best to kick off Saturday Night Live's 40th Anniversary special on NBC: sing and dance. The pair introduced the night with a rousing run down of some of the sketch show's greatest hits, their simple monologue patter transforming into "The Chronic-what?!-cles of SNL," a "History of Rap"-style verse comprising catchphrases from "Schwing!" to "Schweddy balls."

The bit, however, was urgently interrupted by Rachel Dratch's Debbie Downer, who offered a friendly reminder that episodes that start with a musical number often go south quickly. Still the show must go on: To the tune of "Soul Man," Fallon and Timberlake busted out their best Blues Brothers impressions, then shook off an early snap of exhaustion with a prescription shot of  cowbell that garnered a libidinous armpit sniff from everyone's favorite superstar, Mary Katherine Gallagher, played by Molly Shannon.

Fallon and Timberlake ended the opener with a spirited top-hatted, canes-winging conclusion. "It's time for comedy, it's time to celebrate, all the night's we stayed up late, it's been 40 years!" the duo harmonized, closing out the big number with, what else: "Live from New York, it's Saturday night!"

As Fallon and Timberlake also teased, Saturday Night Live's 40th Anniversary special will boast a metric ton of special guests, including Kanye West, Paul McCartney, Taylor Swift, Paul Simon, Tom Hanks, Tina Fey, Maya Rudolph, Jerry Seinfeld, Amy Poehler and Eddie Murphy, who will return to the show for the first time since 1984.