One of the big stories in "classical" music lately has been the resurgence of popular and vernacular musics as a source of inspiration. Some of us (of a certain age) grew up believing that the boundary line dividing the classical from the popular was real, and that it mattered. We assumed that the elite forms of Western concert music, because they aspired to permanent significance, were inherently worth more.

But like many assumptions, this one was both simplistic and short-sighted. For many of the best, most interesting young composers, their map of the musical world no longer features an iron curtain dividing classical from popular. The checkpoints have been dismantled. Visas are no longer required. The term crossover already sounds quaint: what is being crossed over?

With these new-old attitudes now in the ascendant, we'll have to be careful not to make the same old mistakes all over again. It is troubling to see signs of a campaign by some overzealous critics and some over-timid listeners to reject wholesale any music they can damn as cerebral, atonal, serialist, modernist, academic, or inaccessible. It threatens merely to exchange one set of intolerances for another. Where once tonality was forbidden, now it would be expected. Where populism was disreputable, it would be the new orthodoxy.

Of course, categorical oppositions like these turn out to be worthless as predictors of the musical experience. The ovations that greeted the return of the Lutoslawski Fourth Symphony last season (a Los Angeles Philharmonic commission that we premiered and recorded back in 1993) were for an atonal work devoid of popular references. There was an equally fervent ovation for Osvaldo Golijov's St. Mark Passion the season before, apparently its opposite in every way. What these two works have in common is not their sources, their methods, or their sounds. It is their authenticity - what Alex Ross in The New Yorker recently called the force of Golijov's "dire conviction."

Our current and recent seasons have been remarkably ecumenical on this score. This year we have heard persuasive new orchestral works by John Adams and John Williams, both tonal, but we will also hear equally impressive new atonal ones by Magnus Lindberg and Liza Lim in the months ahead. Only a week from now, the Green Umbrella series will continue with music by one composer deeply involved with folk music (Judith Weir), two others whose development was importantly shaped by rock (Steven Mackey and Christopher Rouse), and one who has avoided both those influences (myself).

In the case of Golijov, one of the most talked-about and admired composers in the world and an increasingly frequent presence on Los Angeles Philharmonic programs, it is safe to say that what exhilarates his listeners is not that his music is so "popular," but that it is so good.