OK, I admit it. I'm easy. Even the name Mr. Spacky makes me laugh. But Emily Schwartz's exquisitely silly, genuinely witty new melodrama for the Strange Tree Group--a "murder-muzical" in which the audience decides the ending--bears out the title's promise. Despite Mr. Spacky's star billing, the story belongs to three female characters: a gullible bride-to-be and her future sister-in-law and niece, icy Mrs. Dumont and needy daughter Edwina. In a jocular twist, Mr. Spacky is the hysteric. Lovingly crafted set pieces by a bevy of artists create the play's fanciful 100-year-old world, eroded by an unnamed war, while a seven-piece band provides vaguely archaic music. As Mrs. Dumont, unblinking, cold-bloodedly slow Carol Enoch is deliciously reptilian. --Laura Molzahn a Through 6/23: Thu-Sat 8 PM, Sun 5 PM, Chopin Theatre, studio stage, 1543 W. Division, 773-489-4773, $15-$20, industry shows Thu.