This is brilliant. Fred Armisen was on Jimmy Fallon to promote season 3 of Portlandia, and the the two of them did a hilarious bit about their former bands. What I love about this sketch is that, aside from the album covers and band names, they’re improvising the rest of the material on the spot, and the band is right there with them.
Update: Here’s another example of killer improv on the teevee – Kristen Wiig and Will Ferrel at the Golden Globes out to prove they’ve seen all the films in their category. Tommy Lee Jones is not amused.