Zubin Mehta walks onstage more slowly than he did in his youthful, dashing days and is helped by a cane. Zubin Mehta conducts the L.A. Philharmonic in Mahler’s Third Symphony at Walt Disney Concert Hall Where does Mehta Sound come from? He once came to my performance of Mahler’s Fifth and didn’t like it.” Zubin Mehta conducts the L.A. Phil …