Fresh in the glow of its 50th anniversary celebration, kicked off by a party a few nights earlier and extending through the end of the month, Nighttown put its eclecticism fully on display February 10, presenting powerful Scandinavian free-jazz group Atomic. The Nighttown faithful are, by and large, a straight-ahead crowd (two Manhattan Transfer shows set for Friday, February 13, sold out well in advance, for example), so it’s good to see the folks there are still willing to push the envelope—it is, in fact, part on the club’s vitality. Atomic, in just their second visit to Cleveland—the first a 2004 go at the Beachland Ballroom—made that vitality palpable, exploding with an orchestrated chaos that the 30 or so in attendance will likely not soon forget.