Gustavo Dudamel is only 26, and won’t yet be 30 when he takes over the music directorship of the LA Philharmonic in 2009. But the Phil has a long history with young conductors, and its collection of music directors has been quite a diverse one by orchestral standards, which seems somehow appropriate for the City of Angels. “Los Angeles and its environs are not one thing culturally — nor two, nor 20, nor even 200. The area is not the sum of its parts — it’s a kind of uber-multicultural metropolis.”