Glass turned to smaller music theatre projects such as the non-narrative Madrigal Opera (for six voices and violin and viola, 1980), and The Photographer, a biographic study on the photographer Eadweard Muybridge (1982). Glass also continued to write for the orchestra with the score of Koyaanisqatsi (Godfrey Reggio, 1981–1982). Some pieces which were not used in the film (such as Façades) eventually appeared on the album Glassworks (1982, CBS Records), which brought Glass's music to a wider public. The "Portrait Trilogy" was completed with Akhnaten (1982–1983, premiered in 1984), a vocal and orchestral composition sung in Akkadian, Biblical Hebrew, and Ancient Egyptian. In addition, this opera featured an actor reciting ancient Egyptian texts in the language of the audience. Akhnaten was commissioned by the Stuttgart Opera in a production designed by Achim Freyer. It premiered simultaneously at the Houston Opera in a production directed by David Freeman and designed by Peter Sellars. At the time of the commission, the Stuttgart Opera House was undergoing renovation, necessitating the use of a nearby playhouse with a smaller orchestra pit. Upon learning this, Glass and conductor Dennis Russell Davies visited the playhouse, placing music stands around the pit to determine how many players the pit could accommodate. The two found they could not fit a full orchestra in the pit. Glass decided to eliminate the violins, which had the effect of "giving the orchestra a low, dark sound that came to characterize the piece and suited the subject very well". As Glass remarked in 1992, Akhnaten is significant in his work since it represents a "first extension out of a triadic harmonic language", an experiment with the polytonality of his teachers Persichetti and Milhaud, a musical technique which Glass compares to "an optical illusion, such as in the paintings of Josef Albers". Glass again collaborated with Robert Wilson on another opera, the CIVIL warS (1983, premiered in 1984), which also functioned as the final part (the Rome section) of Wilson's epic work by the same name, originally planned for an "international arts festival that would accompany the Olympic Games in Los Angeles". (Glass also composed a prestigious work for chorus and orchestra for the opening of the Games, The Olympian: Lighting of the Torch and Closing ). The premiere of The CIVIL warS in Los Angeles never materialized and the opera was in the end premiered at the Opera of Rome. Glass's and