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."
La Scala of melody one can catch. La Scala was originally illuminated with 84 oil lamps mounted on the stage and another thousand in the rest of theatre. To prevent the risks of fire, several rooms were filled with hundreds of water buckets. In time, oil lamps were replaced by gas lamps, these in turn were replaced by electric lights in 1883. The original structure was renovated in 1907, when it was given its current layout with 1,987 seats. In 1943, during World War II, La Scala was severely damaged by bombing. It was rebuilt and reopened on 11 May 1946, with