Petr Kotík is by any measure one of the most interesting musicians to emerge from the Czech Republic in the latter half of the 20th century. Born in Prague in 1942, the son of painter Jan Kotík, he was educated in Prague music schools and by his early 20s was notorious. Recalling a performance of his Music for 3 at the Warsaw Autumn Festival in 1964, he says, "The audience tolerated the piece until about halfway through, then all hell broke loose. Half of the audience walked out, including the official composers' delegation from Prague. People ran on stage trying to put a stop to it."

Thus was launched a career in modern music that took off when Kotík moved to the United States in 1969 and fell in with avant-garde composers such as John Cage and David Tudor. Kotík began turning out works like Many, Many Women, a six-hour piece based on the writings of Gertrude Stein. He founded ensembles with which he toured the world, performing rarely heard — some would say unlistenable — works by Cage and other contemporary composers, and generally bending ears and brains from New York City to Prague to Buenos Aires.

Kotík is back in the Czech Republic this month for Ostrava Days, a biannual three-week seminar he organizes that gives promising young composers a chance to study under accomplished masters such as composers Alvin Lucier and Louis Andriessen and conductor Zsolt Nagy. He deliberately keeps the mix international: "I personally called seven very good students in the U.S. to apologize for not taking them, but I don't want this to turn into an American seminar." The 13 Americans who did make the cut are joining 26 other students from far-flung points such as Macedonia, Romania and Iceland for two weeks of intensive workshops.

What makes all this interesting for the general public is the culmination of the workshops in a week-long series of performances featuring student compositions and works by Cage, Edgar Varese and other modern music composers. Literally every concert offers an opportunity to hear seldom-performed pieces, with an emphasis this year on full orchestral works, which are especially difficult to organize and execute properly.

"When we order these huge orchestral pieces from the publisher, it's not unusual to find they've only been performed once," Kotík says. "When you get the score, you see why."

This year's program is heavy on Morton Feldman, Luigi Nono and Iannis Xenakis, with tasty selections from Cage, Kotík, Varese, Pierre Boulez, Erik Satie and the Czech Republic's Martin Smolka in the mix. Excellent musicians and conductors abound, as do exceptional programs. The opening night (Sunday, Aug. 21), for example, features Cage's Atlas Eclipticalis and Winter Music performed simultaneously, and Kotík's Variations for Three Orchestras.

Why is all this being held in the remote reaches of east Moravia? Partly because of Kotík's partnership in the Ostrava Center for New Music, and partly because of his very strong and very negative feelings about the quality of classical music in Prague. "Any time is the worst," he says when it's pointed out to him that the current offerings in the city are among the weakest of the year. Still, aren't there good moments during the regular season? "Even on a garbage heap, you can have an occasional rose," he says with a dismissive shrug.

Call it what you will — arrogant, outré, beyond the pale — this is a gathering of musical luminaries, with a performing component that allows the public to sample the fruits of the musicians' labors. Whether anyone actually comes to hear it doesn't worry Kotík, either. "I'm used to being at historically important concerts attended by only 15 people," he says.