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."
City Opera House (Traverse City, Michigan) three-story, building constructed of red brick. It measures on each side. The ground floor houses commercial tenants; the opera house proper is located on the upper floors. Since completion of the restoration, the City Opera house has seating for 710 people, arches with trompe l'oeil clouds and a dome ornamented with angelic putti, a two-story oriel window, an acoustic stage shell, modern theatre rigging and complete facilities for catered events. City Opera House (Traverse City, Michigan) The City Opera House is located at 106-112 Front Street in Traverse City, Michigan. It was designated a Michigan State Historic Site in 1971