Actor, author and stand-up comedian Demetri Martin is one of those unconventional comedians who rely on clever one-liners, a hefty dose of the absurd — and whimsy, sometimes with drawings on a large pad or playing instruments from toy bells to a ukulele — plus plenty of sheer awkwardness. His new tour is even called Let’s Get Awkward. A Steven Wright devotee, he’s made fans as a contributor on “The Daily Show with Jon Stewart” and from his Comedy Central show, “Important Things with Demetri Martin.” And he’s likely to make even more new fans in the live setting at the National on Sunday, Aug. 27. $37.50. thenationalva.com.