Whistling has always struck me as something that’s fun only for the whistler. And this documentary from Kate Davis and David Heilbroner on the history of whistling and its international competition in Louisburg, North Carolina, did little to make me feel otherwise. There’s whimsy, sure, as you’d expect from an exploration of any anachronistic mini-culture, and you’ll hear some seriously talented whistlers. But the history, anthropology, and physics lessons feel like filler for the competition plot line, which does have its moments. The primary competitors — a turkey farmer with a great gobble, an investment banker who wants to take the title for the fifth year running, an asthmatic Key Wester with a mellow tone and attitude, a confident pro whistler, and a chubby, curly-haired Dutchman — pucker up for the judges. The shots of their performances are way too long; we get it they can trill and oodle and chirp and use vibrato to great emotional effect. And the gloaty, bow-tied banker is so loathsome, you’ll want to punch him in the kisser.