Opening its 61st season with a highly popular contemporary musical with good casting has paid off for California Musical Theatre’s Music Circus. “The Producers,” which opened Tuesday night, involves a failed Broadway producer whose most recent show closed on opening night. A passing remark by the low level accountant sent in to audit the books puts the plot in motion. If the producer would have a guaranteed flop, they could bank the investment, close the show and keep the money. They set out to find the worst play, a lousy director and terrible actors. Many complications and much humor ensue, along with lots of great songs and dancing. “The Producers: the new Mel Brooks Musical,” while b