Ken Ludwig's tender Depression-era farce centers on a hungry "dogsbody" understudy, Max, who craves opera's limelight. A plucky, lovable impostor, he wins fame and love because of a cascading series of calamities in Cleveland. And under Justin Amellio's direction for the One Theatre Company, the hotel doors bang big-time (a knob burst off on opening night). The casting is cunning, the energy rambunctious--and that's a problem. This loud show becomes claustrophobic: instead of being pulled in, you pull back. And because it goes overboard early on (especially with the Italian stereotypes), never quite establishing the bedrock from which burlesque departs, it doesn't build well. But Matt Dyson's Max charms--we never stop rooting for him. Through 10/8: Thu-Sat 8 PM, Sun 2 PM, Athenaeum Theatre, second-floor studio theater, 2936 N. Southport, 312-902-1500, $20-$25, 2-for-1 industry shows Thu.