 Itzhak Perlman (qv) was a surprise guest at this concert. He  appeared not as a violinist but as a vocalist, making his singing  debut in the baritone role of the jailer in an excerpt from  Giacomo Puccini (qv)s opera, "Tosca". After the concert ended,  Perlman, at the request of conductor Zubin Mehta (qv), did play an  encore on the violin 