The Théâtre des Champs-Élysées, which opened in 1913, is a 3,000-square-metre, five-part complex including a 1,200-seat main performance hall. The Perret brothers had already designed several groundbreaking projects, but this one thrust them into the vanguard of modern architecture. Roger Bouvard's original plans, revised by Henry Van de Velde, called for a stone building. The Perret brothers innovated by opting for an exposed concrete skeleton, which immediately sparked controversy: it shattered the architectural conventions of what a "French-style" theatre should be. Fortunately, the main auditorium soon earned a reputation for excellent acoustics, which Auguste Perret had theorised, and which the press covered. The Perret brothers' archives, which were given to the Conservatory in 1956, contain the famous axonometric view of the theatre's skeleton drawn by Auguste Perret in 1913, upon which this model is based.