Why are classical concert audiences eroding? Composer Libby Larsen has been studying the problem, and has some ideas. For one thing, suburbanites (and a majority of the population in most metro areas lives in the suburbs) already make an average of 13 car trips a day, and aren’t terribly keen on battling traffic into the urban core for a concert. For another, technology and its constant advance means that even hardcore music-lovers don’t actually need the concert hall to get their fix. And then, of course, there’s the repertoire problem…