Crosby, Stills and Nash get "Fancy" with Jimmy Fallon

Crosby, Stills and Nash got "Fancy" on "The Tonight Show with Jimmy Fallon" Monday night.

David Crosby, Stephen Stills and Graham Nash lent their harmonies to a rendition of the Iggy Azalea summer hit. Fallon accompanied the trio doing his best Neil Young. So it was almost like a CSN&Y reunion. Almost.

Fallon is known for getting his guests to play along with renditions of popular songs. He's successfully done it with Bruce Springsteen with "Sexy and I Know It" and "Whip My Hair."

Crosby, Stills and Nash just released a re-mastered box set commemorating a 1974 tour with Young.