The job of ballet conductor is far more than a simple stick-waving exercise. Synchronizing music and dance is a tremendously difficult undertaking, and it takes a cool head and a keen eye to adjust an entire orchestra to the sometimes unpredictable whims of the performers on stage. So it was a bit of a surprise when San Francisco Ballet tapped an unusually young man to be its new pit conductor, but 37-year-old Martin West loves a challenge, and initial reviews have been overwhelmingly positive.