Pink Venice.

The announcement of the event was spread in the beginning of April 1989, triggering a bitter polemical debate in the following three months, particularly concerning the city's decorum and the fear that the excessive volume of the music could damage its artistic heritage. The Superintendency of Cultural Heritage therefore set a limit of only 60 decibels so as not to damage the Byzantine mosaics of St. Mark's basilica [...]

Wikipedia: Pink Floyd in Venice: A Concert for Europe