To paraphrase Spinal Tap’s Nigel Tufnel, there’s a thin line between genius and stupid, one that Peter Mills and Cara Reichel walk with flair in The Rockae, their rock adaptation of Euripides’s The Bacchae, part of the NYMT fest. The opening tableau illustrates the promise and danger of the premise, as Dionysus (Michael Cunio) takes the stage in high-’70s regalia, his hair cascading and torso gyrating to the arpeggiation and thrash of Mills’s score. The moment encapsulates the uneasy blend of self-parody and pure, yes, Dionysian revelry that characterizes this musical. At its best, the show simply rocks, performing a misty mountain hop up Mt. Olympus. Songs like the aptly named “Let the Bedrock Rock” show off the vocal power of the ensemble, making good on the premise that rock opera just might be the best way of conveying the intensity of Greek tragedy to a modern audience. At less inspired moments, though, watching The Rockae can leave one feeling trapped in Camille Paglia’s unconscious, enacting a dated tribute to the pansexual potential of the electric guitar. Cunio’s languidly feline demigod is oddly matched with Mitchell Jarvis’s feisty King Pentheus; though each enjoys a piercing tenor that helps underscore the play’s gender confusion—soaring above the tones of the female accompanists—even their most direct confrontations remain evasive. All the same, The Rockae drives home a point on which Euripides and Ozzy would agree: Compared with the frenzied powers of the gods, the rational mind’s just not all that.