Before there was James Franco, there was Jeff Goldblum. OK, the comparison isn't quite appropriate, but maybe this clip of him performing "Just a Friend" with Biz Markie and The Roots will help change skeptical minds.
Oh, and Jimmy Fallon joins them as well — it takes place on his show, after all. And also, the entire audience participates too. They did [probably] wait in line for hours to get in, right? And one more thing — you'll join in as well, because it's extremely difficult to not sing along when "Just a Friend" is playing at any place, at any time.