Opera house electronic libretto systems have begun to be used in some opera houses, including New York's Metropolitan Opera, Milan's La Scala, and the Crosby Theatre of The Santa Fe Opera, which provide two lines of text on individual screens attached to the backs of the seats so as to not interfere with the visual aspects of the performance. A subtle type of sound reinforcement called acoustic enhancement is used in some opera houses. Acoustic enhancement systems help give a more even sound in the hall and prevent "dead spots" in the audience seating area by "...augment[ing] a hall's intrinsic acoustic characteristics."
Metropolitan Opera House (Philadelphia) Academy of Music for the 1920-1921 opera season, the MOH became the home of the Philadelphia Civic Opera Company until 1928. The Philadelphia Grand Opera Company and the Philadelphia La Scala Opera Company, two companies that primarily performed at the Academy of Music, also occasionally performed there during the 1920s and 1930s. The MOH was also host to many traveling productions by opera companies from other cities. The last opera production mounted at the MOH was a double billing of "Cavalleria rusticana" and "Pagliacci" under the baton of Aldo Franchetti, presented by the Chicago Grand Opera Company on May 5,