Schoenberg’s Moses und Aron is a very peculiar opera. It’s pretty much an extended debate about the nature of God cast in highly abstract terms. So who better to direct it than the almost unbearably cerebral Romeo Castellucci. Previous encounters with his work have been puzzling, thought provoking (and WTF provoking) but never dull. All those terms could be deployed to describe the production recorded at L’Opéra nationale de Paris in 2015.