Avant-classic

I can't imagine the musical landscape without him," says Ursula Oppens, one of the finest pianists specializing in contemporary music. She's referring to György Ligeti, the 81-year-old Hungarian composer whose pieces—humorous, morose, knotty, percussive—have outgrown the new-music ghetto in the last 50 years. They have become a standard part of a musician's training. Despite the daunting nature of some of them, which, on paper, look almost impossible to execute, Oppens says performers and audiences have turned Ligeti into "an absolute classic." Pianists learn his études—some of which have been performed here, most of which haven't—and the Chicago Symphony performed the Chamber Concerto three seasons ago. The Chicago-based Callisto Ensemble is devoting this season to him.

Cliff Colnot, Chicago's jack-of-all-musical-trades (conductor of many groups, advertising-jingle writer, arranger, coach of student ensembles), is conducting Ligeti's Chamber Concerto with the Callisto Ensemble on January 30. He shares Oppens's Ligeti enthusiasm. "I would put him up there in the pantheon of great composers that most people can agree on," he says. "He's not highly derivative and not someone who has gotten on a bandwagon and leveraged it for his own benefit. His voice has gone through a metamorphosis, but remains special, identifiable and profound."

Oppens performs Ligeti's Horn Trio on Friday 20 with colleagues from Northwestern. That work shows the metamorphosis in Ligeti's voice which Colnot mentions. Previously, Ligeti created hazy masses that sounded like electronic music, only played by acoustic instruments. (The most famous of these is 1961's Atmospheres, which Stanley Kubrick tossed into 2001: A Space Odyssey.) By 1982, the year he wrote the Trio, he had found something else.

Brahms wrote the most famous Horn Trio, and, sure enough, Ligeti's Horn Trio is subtitled "Hommage to Brahms." Always the iconoclast, Ligeti wrote a march movement, but the horn plays at a different speed than the piano and violin, destroying the idea of people moving in unison at the same pace. The final movement is marked Lamentoso, a marking Brahms never used. Still, "It's almost the saddest piece I've ever played," says Oppens.

The Chamber Concerto, from 1969, is more abstract than the Horn Trio, so instead of recognizable forms like marches and laments, there is lots of fast counterpoint between the 13 instrumentalists. Where Brahms might divide a beat so that there are two or three notes inside it, then play both divisions at the same time, Ligeti often has divisions of five and seven or seven and nine going on simultaneously. Colnot won't apologize for the piece's difficulty, which, it should be said, is harder for the performers to execute than for the listeners to hear. "I think it's a masterpiece," he says, before explaining how he gets an ensemble to handle the rhythmic awkwardness. First, "it has to be deconstructed into a very slow tempo so that they can hear the imitation of the entrances," e.g., so the clarinet can follow the flute.

Once that's in place, the group can play it faster and faster while still hearing where each individual fits in. "If you do it too fast at first and they don't understand where their second and third of the triplet relates to the fourth of the septuplet, then you might as well give a downbeat and [just] let everybody play," says Colnot.

Along with the ensemble dilemmas, the individual parts are hard just on their own. If the fast woodwind parts aren't played smoothly, they become "lumpy and bumpy and you hear a lot of key noise and grunting and wheezing," says Colnot. But when they're done well, Ligeti's music floats and twists in unexpected, eerily pleasing directions.

Despite the technical challenges Ligeti raises for performers, they obviously relish digging into them. Oppens gets giddy when talking about how Ligeti, an amateur pianist, conjures up technical conundrums that a real pianist wouldn't dream of; Colnot is fascinated to work on "deep, deep music" with serious performers. The rest of us get the satisfaction of hearing musicians play music they love.

Ligeti's Horn Trio isplayed at the Northwestern Winter Chamber Music Festival Friday 20.