What’s the “right” sound for an American opera? In setting A Streetcar Named Desire, André Prévin scoffed at following the explicit music cues Tennessee Williams wrote into the script and instead took inspiration (or so he told me) from Wozzeck of all things. Ricky Ian Gordon’s approach to John Steinbeck’s Dust Bowl epic The Grapes of Wrath has been quite the opposite—his palette combines the usual orchestral sonorities with the homespun sounds of banjo, guitar, harmonica, saxophones, and barroom piano. MasterVoices, which produces indispensable concert performances of American musical theater works not to be seen in full-dress stagings, gave the New York premiere of The Grapes of Wrath in 2010 under the baton of Ted Sperling. In his 10th season as MasterVoices’ indispensable music director, Sperling now premieres Gordon’s Steinbeck in a revised edition that includes touchups and a whole new aria. As usual, the casting is masterly (pun unintended but wholly appropriate), showcasing singing actors who move freely between opera and musical theater. Nathan Gunn—dynamite as Rossini’s Fígaro and Lerner and Loewe’s Lancelot—plays Pa Joad. Mikaela Bennett—whose credits include Handel’s Israel in Egypt as well as Maria in West Side Story—is Rose of Sharon. —Matthew Gurewitsch