Cellist Timothy Hugh, a principal of the BBC Symphony, ended his latest performance with a flourish of splintering wood when he flung his cello to the ground and jumped on it, Reuters news agency reported Wednesday. Along with other string players in the orchestra, Hugh was unhappy during rehearsals with an avant-garde piano concerto by German composer Helmut Flammer. In an unscripted finale, Hugh took revenge on a substitute cello, provoking a chorus of boos for the composer from fellow players. The scene caused uproar in the audience of about 100 contemporary music enthusiasts. Some of them thought the cello-smashing in the recording studio was part of the score.