Oakland Opera Theatre exists as a vehicle for modern opera. Since it took on the Oakland Opera name in 1999 (the former Oakland Opera having shut down a few years earlier), the company’s offerings have ranged from Gertrude Stein and Virgil Thomson’s “Four Saints in Three Acts” to a disco-era staging of Stravinsky’s “The Rake’s Progress” to a circus fantasia of Glass’ “La Belle et la Bête.” Seeing what inventive stagings the small company concocts with limited resources is half the fun…”