ALEX ROSS Scourge of mediocre elitists.

New Yorker classical-music critic Alex Ross is the most surprising spokesperson for an increasingly influential progressive wing in the classical-music establishment. He once described classical-music concerts as "mass anal retention," and began his cult-hit 2004 essay "Listen to This" by blurting, "I hate 'classical music.'"

This is a guy who studied piano and composition and didn't start listening to anything but Beethoven and company until age 20 (he's 38 now). Ross hasn't turned against the music, but rather the "cult of mediocre elitism" that has strangled it for decades, from the unnecessary stiffness of concert-hall behavior to the absurd institutional ban on new music. New music hasn't acquired the patina of self-importance, so it doesn't belong in the "classical" world, according to those who hawk antique music as though it were a high-heeled shoe that will lift its listeners above the gutter of mass culture.

"They gesture toward the heavens," Ross writes, "but they speak the language of high-end real estate." Or: "The American middle class carried the worship of the classics to a necrophiliac extreme."

Ross wants to call it simply "the music," like jazz lovers do. He wants to talk about it as if it were popular music, without the pretentious Italian words and the endless musicological descriptions that clog American mainstream classical-music criticism and contaminate the concert experience, starting with the program notes. "Yes, the music can be great and serious; but greatness and seriousness are not its defining characteristics," Ross writes. "It can also be stupid, vulgar, and insane."

Most importantly, it can be recent.

On the Boards—notably, not the Seattle Symphony, which rarely ventures forward from Shostakovich and Bartók—has invited Ross to deliver a presentation called "My 20th Century (An iPod Lecture)," which endeavors to do what orchestras have not: bring an audience up to speed on the wildly varying music of the last 100 years. I saw this presentation in a prototype version Ross did for a private group of music journalists in 2004, and it was terrific—equally entertaining and edifying.

Ross has been working on a book to be released next year by Farrar, Straus and Giroux that's ostensibly about 20th-century music, but is really about the events of the era seen through the music of garden-variety atonalists such as Schoenberg and Berg; electronica progenitors such as Varése; and people such as populist tunesmith Kurt Weill, Conlon Nancarrow (whose writings were so complex that they could only be performed by player piano), and communist freedom fighter and noise artist Iannis Xenakis. Of course, the minimalists are there, with counterparts in rock such as the early Velvet Underground members, and there's opera, jazz, microtonalism, folklorism, communist anthems, Woody Guthrie, and Björk.

The iPod tour of 40 to 50 clips veers from lucid, in-the-score arcana to speculations about how Schoenberg's wife's lover's suicide coincided with the first piece he wrote that made no reference to a musical key. It starts around the same place as the book: at the 1906 Austrian premiere of Richard Strauss's opera Salome, where Mahler, Puccini, Schoenberg, and the teenaged Hitler were in attendance.

"People have this picture of classical music as this strange, geeky little ghetto, but it had these really dramatic collisions with 20th-century history," Ross says in a phone interview. "Everyone comes into the story, which is why my book is 100,000 words too long."

He wants to convey that composers couldn't be further from the "global conglomerate" of the super-rich attached to grand opera houses and concert halls. They've often been outcasts, or in the case of Harry Partch, hoboes.

But the best part is hearing music that really isn't played anywhere.

On the Boards artistic director Lane Czaplinski invited Ross "for purely selfish reasons."

"I'm interested in what the classical music of our time will be, but I don't want it to be a lame, safely considered music," Czaplinski says. "I want composers today to have a forum, and I want to get people to consider these classifications differently. When I hear a piece of classical music that particularly kills me, you know the kind where you cry and you quiver and you roll up on the floor and go fetal, I mean, that's what I'm looking for, and I want people to continue to make that."