Philip Glass is not only—without any serious rival—the most famous living American classical composer. He is arguably the most famous such composer in the world. His instantly recognizable music is heard constantly in concert halls, opera houses, ballet performances, live theaters, and movies—not to mention in countless homes on numerous CDs or DVDs. His personal chamber orchestra, the Philip Glass Ensemble, tours the world usually to perform at lavish multimedia events. Reaching diverse listeners from punked-out kids to Armani-clad executives that would not normally sit in the same auditorium, Glass is America’s ultimate crossover artist. What other classical composer simultaneously struts his stuff at the Metropolitan Opera, the Brooklyn Bang-the-Can Festival, the Roxy Cineplex 10, and Saturday Night Live?

San Franciscans will have the chance this month to experience Glass’s film music under ideal conditions. Two special screenings will be presented at Davies Concert Hall. Rather than hearing the scores on the original soundtracks, audiences will encounter them live by the Philip Glass Ensemble conducted by the composer. The first program (Oct. 13) features Koyaanisqatsi, his groundbreaking collaborating with director Godfrey Reggio. The second (Oct. 14) presents six short films, including works by Peter Greenaway and Atom Egoyan, culminating in the 27-minute Anima Mundi, a lyric film of astonishing beauty.

The sheer scope and diversity of Glass’s career make him difficult to describe within the conventional terms of the classical music world. Other notable composers, like Lou Harrison and John Adams, have critical reputations. Glass, like Calvin Klein and Martha Stewart, has a brand name. Ambitious, prolific, and astonishingly successful in reshaping the tradition-bound institutions of “serious” music, Glass resembles no classical musician of his time. The cultural figure he comes closest to is painter-photograph-entrepreneur Andy Warhol, the white-haired wonderboy, who with his “Factory” entourage of friends, freaks, and factotums changed the definition of what it meant to be an artist in modern America.

Like Warhol, Glass has understood that fame is the true currency of the arts world. Both men also sadly knew how little fame could be garnered quickly within a single artistic medium, especially a traditional high-art form like painting or classical music. (Nowadays a “famous” composer is mostly famous only to other composers.) And both had a singular genius for marketing and financing new ideas that were both artistically interesting and commercially successful. Not surprisingly, both men were irresistibly drawn to the central American art form—the only one that everyone really knows and loves—the movies. Here, however, the comparison between these two innovators falls apart—and in Glass’s favor. Warhol made dozens of monumentally pretentious bad films from the interminable ennui of Sleep (1963), eight snore-packed hours of watching a man snooze, to the meandering vulgarity of Trash (1970) and Andy Warhol’s Frankenstein (1974). No director in human history has ever or will ever make worse movies. Warhol makes Ed Wood look like Ingmar Bergman.

Glass, by contrast, has collaborated on creating several innovative cinematic masterpieces. While has he composed excellent scores for serious commercial films like Paul Schrader’s Mishima (1984), Martin Scorsese’s Kundun (1997), and Peter Weir’s The Truman Show (1998), his central achievement has been to reinvent the contemporary experimental film. In this endeavor, he had the either the great luck or astute judgment to link up with the then novice director Godfrey Reggio, a New Orleans-born former Catholic monk turned TV producer. Reggio had limited cinematic experience but a visionary imagination worthy of St. Francis of Assisi. Working with Glass, he created a now classic trilogy of non-narrative films, two full-length features, Koyaanisqatsi (1983), Powaqqatsi (1988) and the shorter Anima Mundi (1992).

Once again conventional terminology is inadequate to describe these odd and breathtakingly beautiful films. They are not documentaries, but extended visual celebrations of the natural world and indictments of modern technological despoliation. A skeptical soul, I automatically suspect any movie with a title like Koyaanisqatsi (a Hopi term for “life out of balance”), but the film earns every bit of the renown it has gained. Working for nine years, Reggio created a stunning collage of images which he then meticulously cut to Glass’s powerful motoric score. Insistent, lyrical, and mysterious, Koyaanisqatsi and Anima Mundi rank as masterpieces of experimental cinema. (Powaqqatsi is less impressive in—not coincidentally—both musical and cinematic terms.)

Glass’s film work reveals his obsession with mixing art forms—especially unlikely ones. Who else would have written a musical score for Tod Browning’s Dracula (1931), the classic Bela Lugosi film (which bestowed on all future media vampires a Hungarian accent)? The original movie had no background music, so Glass composed a tense and spiky non-stop accompaniment for the Kronos Quartet, classical music’s equivalent of Green Day. First done live, the score was then recorded on a new version of the film. He went one step further with Jean Cocteau’s La Belle et la Bête (1945). He wrote an opera in which live vocalists on stage sing the French dialogue being spoken in the film—the radical opposite of lip-syncing—an approach which the composer rightly calls “an entirely new kind of music/theater.” The effect in performance is so powerfully dramatic that the question of the music’s independent quality seems beside the point.

Perhaps the most revelatory Glass hybrid concept was his “Low” Symphony (1992), which used melodies by David Bowie and Brian Eno to create an ambitious forty-two minute classical composition. As the work’s title announces, Glass has consistently tried to break down the conventional distinctions between high and low culture. As a modern American, Glass listened to all sorts of music from jazz and rock to traditional and experimental classical. Why limit the material he employed in his own work to one fraction of the whole musical universe? What George Gershwin did for jazz, Glass did for rock. He used it as the raw material to reinvent a new and truly contemporary sound in classical music.

One can hear rock music’s influence nearly everywhere in Glass’s compositions—the driving rhythms, the simple harmonies, and the bluesy lyricism. Surely, one reason audiences respond so strongly to his sound is that they recognize and understand its roots. For decades much “serious” modern music admonished the audience with astringent sounds of enormous complexity. Even a sophisticated audience member couldn’t help wonder for whom these academic avant-garde composers thought they were writing. Fellow academics? Extraterrestrials? Certainly not you or me. In contrast, Glass sounds as if he has been living in the same world as the rest of us.

Praising Glass’s artistic daring, theatrical ingenuity, and admirable energy, however, I can’t help coming back to the music—not as a cultural statement or avant-garde experiment but just as, well, music. After all, creating memorable and moving music is what composers are supposed to do. The problem with Glass is that his musical ideas are rarely as good as his overall artistic concepts. However fascinating to witness his enterprises in performance, they seldom reward pure listening.

I don’t mean to disparage his work entirely. Glass has created an original and attractive sound and style—something few composers manage in any age. One can immediately recognize his music and not only by its minimalist simplicity. Nearly all of Glass’s music possesses an extraordinary emotional intensity. He is also a brilliant and innovative orchestrator, creating a sound that is both preternaturally clear and physically acute. He may repeat certain orchestral tricks a bit too often—but so did Bach and Mozart. What matters is the expressive power of each work.

The trouble with Glass’s music is that it doesn’t seem to go anywhere. His greatest musical innovation was to take the parts of music one normally considers accompaniment—the rhythm and the harmony—and make them the central content. He rarely offers melodies in any conventional sense. There is also no development of musical ideas—which is perhaps the classic tradition’s most significant achievement in world music. What Glass offers instead are colorful, emotive, but largely static blocks of gorgeous sound. His Minimalist aesthetic is based on obsessive repetition. The same musical pattern, sometimes a single chord, is played over and over until it creates nervous tension in the listeners. The more closely one listens to his scores the more claustrophobic and constrained they feel as pure music.

There are few Glass works that I can consistently hear with unqualified pleasure—most notably his melancholy Violin Concerto (1987) and his edgy ballet score, Glass Pieces (1983), both of which are relatively short. His operas, like Einstein on the Beach (1976) or Akhnaten (1983), which often run three or four hours, are hard going without their extravagant staging. For me, Glass’s talent is essentially collaborative. Working with the right director or choreographer, he creates stunning total works. To say that his musical scores cannot be played independently without loss does not diminish the achievement of the originals in which they played an essential and usually dominant part. To have helped create Koyaanisqatsi or Anima Mundi is justification enough for any composer.