Julia May Jonas's "Evelyn," at Bushwick Starr Mixing elements of drama and musical theater as well as intimate realism and mythic tragedy, "Evelyn," a jittery new play by Julia May Jonas set in a Pennsylvania mental institution, has a touch of madness. But not nearly enough. Ms. Jonas - who runs the theater company Nellie Tinder, which is producing this show at the Bushwick Starr - not only writes and directs, but also, on the night I attended, gamely and adequately substituted for one of the actors. Her play at first appears to be a genre piece in the style of "One Flew Over the Cuckoo's Nest" or "Girl, Interrupted," following a group of anxious female psychiatric patients thrown into turmoil when a movie star named Evelyn (Hannah Heller) joins their ranks. A master manipulator whose reason for being there is unclear, she finds the weak spot of each patient and begins her wily seduction. There are musical flourishes, including some lovely violin playing, as the plot escalates into a Dionysian frenzy in the woods. While attention-grabbing, this stylistic shift is unconvincingly executed. The tightly orchestrated chants by the cast sound less like a Greek chorus than like a dutiful start to a Passover Seder. Ms. Jonas is interested in the tension between order and anarchy, but when the scenes of institutional banality give way to unleashed passions, the show remains oddly inert. The staging is too neat, the theatrical images familiar (particularly in the critical violent scene) and the musical interludes flat. Ms. Heller needs to be a magnetic force of nature to convince us that she could be such a dynamic catalyst. Instead she seems mannered and controlled, an actor in a loose straitjacket.