Now, what you hear is not a test: this is NBC News' Brian Williams and Lester Holt, rapping the classic old-school hip-hop track "Rapper's Delight," originally by the Sugarhill gang.

Of course, Williams and Holt weren't actually in the studio (Williams is in Sochi, apologizing to Arsenio for leaving him off a late-night monologue). Jimmy Fallon and the crew of the new Tonight Show put the video together, and it smokes. Maybe we shouldn't be surprised—the Williams family is no stranger to rap covers.

Fallon's first week at Tonight has been good so far, at least on the viral-video front. Yesterday he put on a ragtime cover of an R. Kelly song, and on Monday he and Will Smith sent up a YouTube video.