Concert Halls and Opera Houses

The first question any lover of classical music usually asks an acoustician is, "Which are the best halls in the world?" The response -the three halls rated highest by world-praised conductors and music critics of the largest newspapers were built in 1870, 1888, and 1900- always prompts the next query: "Why are those so good while many halls built after 1950 seem to be mediocre or failures?" You w...