“Magnum Opus” is an hilarious and, for anyone close to the arts world, tremendously cathartic show. Incredibly well staged, fantastically acted, and (of course) atrociously written, the show is a satisfying work, far more entertaining than the sum of the words on the page (thank God). I realize it may seem counterintuitive to praise the talents of the cast in a show that is intentionally awful, but that they are able to do so much with such bad material is a testament to their talents. See this show!