We caught up with Charlie Christos, a singer-songwriter who performs in the on-stage band for Prometheus Bound. This brand-new incarnation of Aeschylus’s ancient tragedy recast as a rock show is currently playing at the American Repertory Theater’s Club Oberon in Cambridge. It was directed by Death and the Powers‘ Diane Paulus, with a fresh, lean and direct text by Steven Sater (Spring Awakening) and gut-shaking music composed by Serj Tankian (lead singer of System of a Down). Charlie went to Death and the Powers last Sunday. Here he is backstage at Oberon, talking about the experience.