Three hours to go before the evening's performance and something isn't right. Sitting at a grand piano in St. George's concert hall in Bristol, England, on May 12, Derek Paravicini tears through a rehearsal of The Flight of the Bumblebee , his fingers skittering across the piano keys. The musicians in the Emerald Ensemble orchestra feed off his energy and manage to keep up the pace, but it all sounds a bit off. After several stops and starts, the conductor discovers the problem: the orchestra and the star have been practicing different versions of the same piece.
Any other...