Kevin Johnson's taste in musical theater is dark, a little twisted and ultimately humane. Well, usually; there wasn't much redeeming social value in Ruthless! last January, but there wasn't supposed to be. Every once in a while, we need a show that's just campy and mean. We don't otherwise get that kind of theater on smiley-face Tucson stages these days, to say nothing of commercially risky but touching productions like A New Brain, which Johnson's Arizona Onstage Productions offered in June. The company's per-show budget tops out at about $30,000, but that's obviously enough to allow superb, professional work. Perhaps Arizona Onstage's upcoming third full season can shame other companies into taking more seriously our intelligence and tolerance for the offbeat.