Back to the future! Though the name might suggest otherwise, Teatro Nuovo cultivates theatrical novelty by means of antiquarian, long-abandoned performance practices. To quote from the companies promotional materials, “Teatro Nuovo’s orchestra, like those of Italy in the age of Bel Canto, is led jointly by a violinist and a keyboardist, without a standup conductor.” Ideally, the approach enhances in-the-moment chemistry between singers onstage and instrumentalists in the pit, allowing even for moments of improvised give and take. In recent seasons, critics have been bowled over. “Transformative,” said one. “Revelatory,” said another. This summer’s season juxtaposes Rossini’s epic tale of forbidden love Maometto Secondo against Bellini’s gossamer La Sonnambula, in which a heartbroken sleepwalking heroine awakens to find her dreams come true. —Matthew Gurewitsch