Crosby, Stills and Nash made their first appearance on the Jimmy Fallon-hosted version of NBC's Tonight Show last night (Monday), and they were joined for a surprise performance by "Neil Young," a.k.a. Jimmy Fallon.

After the show Graham Nash said, "He does a better Neil Young than Neil does... He took this pop song [by Iggy Azalea] called "Fancy" and he turned it into a Crosby, Stills, Nash and Young song... He really realizes how lucky we are. I mean, God save us from a real job."

CSN, minus "Young," then did "Teach Your Children," plus a version of "Learn to Live" for the show's website.

CSNY release CSNY 1974, a box set of their 1974 tour, Tuesday. CSN start a three-night run at New York's Beacon Theatre tonight, followed by shows Wednesday and Friday.