Esa-Pekka Salonen is about to take over London’s Philharmonia orchestra, where he had a career-changing experience in the 1980s. “The greatest risk to classical music is not to respond to the culture until one day it just stops. There are some differences in the artistic structures and traditions of LA and London, but the approach that worked in LA was not to dumb down, but to do the opposite, to challenge the audience. And people responded.”