CAPTION: One cost-effective way of reducing vandalism and deterring youths from hanging around at metro and urban railway stations is to broadcast classical music. Playing Bach and Beethoven over the public address system is a method tried and tested from Newcastle-upon-Tyne to Toronto. But Montreal’s metro has taken the art one step further by using the operas of Wagner, Rossini and Puccini to deter punks who were annoying passengers. While Pavarotti is renowned for public performances, Dieter wonders if a live concert would have greater effect