Schoenberg began composing Moses und Aron in the 1920s, and finished the first two of a projected three acts by 1933. He then hit a block, and never finished the third act. Nevertheless, he thought enough of the unfinished project to permit its performance. Since then, it's enjoyed a somewhat uncertain place in the repertory, respected more than it's loved. Moses und Aron is composed in the serial technique Schoenberg pioneered in the early 20th century. That is, Schoenberg selected a "tone-row" of twelve notes — unrelated to each other by conventional harmony — and built the entire harmonic and melodic structure of the opera from various inversions and permutations of that series. The result is, of course, atonal — that's the entire point of serial composing — but Schoenberg spins moments of lyricism, shimmering otherworldliness, and sharp drama from the seminal tone-row.
Schoenberg himself wrote the libretto, which is a very loose adaptation of the episode of the Golden Calf in Exodus. Schoenberg highlights the dynamic between Moses and his brother Aron — Moses is more Hamlet than Charlton Heston. He is a solitary thinker, hesitant and not given to preaching or wonder-working. The Lord reveals himself to Moses and commands him to order the Israelites to worship Him, the single, unknowable, invisible, unimaginable, omnipresent Creator. Moses is frightened and intimidated by this impossible demand — the Israelites want a god they can see and feel, a god whom they can offer sacrifices to and make demands on, a god that lets himself be seen. Moses thus enlists the help of his brother Aron. An expert promoter, Aron beguiles the Israelites with flattery (stressing that God has "chosen" them), and wows them with miracles. The Israelites are temporarily convinced to turn away from their idols, and place their trust in this new, difficult deity. Nevertheless, the conversion is fragile. After Moses ascends Mt. Sinai to commune with the Lord and stays there for 40 days, the Israelites grow impatient, and threaten Aron unless he gives them idols to worship.
Schoenberg greatly embellishes the Biblical armature for the story. Moses and Aron have a symbiotic and uneasy relationship, with Aron usually in the lead role. But that's not the only unorthodox interpretation of the source. For one thing, the chorus of Israelites complain that the new, invisible God — despite his well-known fondness for laws — will himself bring about lawlessness. At least the old, tangible, familiar gods enforced a detailed and enforceable — if bloody — code of conduct. Who will obey a God who refuses to even show himself to his people? Moses himself is more Hamlet than Heston — he spends much of the opera worrying about how to fulfill his divine mission, or communing with the Almighty on Mt. Sinai. It's hard not to see Moses as a commentary on Schoenberg's own situation: the Muse (God) commanded Schoenberg to develop a complex, atonal composition technique (monotheism), thus condemning him to a life of unending struggle against the philistines (the recalcitrant Israelites, who want to hear pretty music).
The choir of the Deutsche Oper am Rhein started practicing for Moses und Aron a year and a half ago, according to a report I heard. No wonder: the choir is onstage for almost the entire opera, and has a fiendishly difficult singing part. But it's not just the singing: in Christof Nel's staging, the fickle Nation of Israel must transform itself, within minutes, from vengeful mob to chaotic orgiasts to stumbling zombies. This they did, convincingly. The set design, by Roland Aeschlimann, is muted and sober: the stage is dominated by a large, curving staircase, and the choir dress in everyday, slightly outdated clothes. The staging team wisely refrained from self-indulgent auteur-theatre gimmicks — in a score which calls for orgies and blood sacrifices onstage, understatement is the order of the day. Nevertheless, the Israelites' unhinged veneration of the Golden Calf — which includes murders and blood sacrifice — builds to a very disconcerting frenzy, as celebrants begin beating each other senseless on the stairs while the orchestra's percussion section fires away.
All in all, a courageous programming decision leading to a fine performance of a difficult but fascinating work. If you're interested, there are still plenty of performances left (g)!