It's taken some time, but "Saturday Night Live" alumnus Jimmy Fallon has developed into the best possible helmsman of Conan O'Brien's former "Late Night" gig. One of his best strengths is his taste in music, evident by having the Roots as his house band and a steady stream of breakthrough artists making guest appearances. Other great musical moments come from Fallon himself, particularly when he impersonates the quintessential "Harvest"-era Neil Young, singing contemplative acoustic covers of songs such as theme from "The Fresh Prince of Bel-Air," "Pants on the Ground," by General Larry Platt, and Willow Smith's "Whip My Hair" (the last of which was duet with a Bruce Springsteen). While it would be amazing to see a Neil vs. Neil showdown someday, the real Neil is as busy as he was decades ago, touring behind his latest album, "Le Noise." Playing songs spanning his career, and supported by a genuine British folk legend (the great Bert Jansch), ageless singer and songwriter Young is scheduled to perform at the Landmark Theater on April 17 at 8 p.m. $55-$200. 800-745-3000.