In a 1960 lecture, composer La Monte Young revealed a lot about his nature when he quipped, "Once I tried lots of mustard on a raw turnip. I liked it better than any Beethoven I had ever heard."

It has been Young's intuition that has pushed back the boundaries of music, with what at first sound like deceptively simple elements -- sustained tones and improvised fragments that create ethereal harmonies, which seemingly float about at will.

And after nearly 50 years of sound exploration, he's earned his status as guru to a generation of classical and rock composers. British composer-producer Brian Eno sums him up best: "La Monte Young is the daddy of us all."

Young's trailblazing instincts prove you can take the pioneer out of the frontier, but you can't take the frontier out of the pioneer.

Which makes sense, considering that Young grew up in a log cabin in Bern, Idaho, and by age 4 was learning to play guitar and sing cowboy songs. But it was the notorious winter winds whistling through the homestead that first really attracted his attention. Telephone wires were not far behind. "Telephone poles make a long, sustained sound, a sound that doesn't have the change of pitch that the wind does," he explains.

Sustained tones, which are at the core of Young's music, will be in abundance tomorrow evening at the Kennedy Center Terrace Theater, where Young will make a rare personal appearance for the world premiere of "The Second Dream of the High-Tension Line Stepdown Transformer" (melodic version) from "The Four Dreams of China," originally written in 1962.

Interested listeners need not fear live wires. Four trumpet players will play only four preselected tones, improvising within strict guidelines established by Young. One need only bring an open mind and ears to appreciate the silvery harmonics that filter in and out of earshot.

These mystical qualities spring from Young's diverse background. In Los Angeles during the '50s he was an acclaimed saxophone improviser, leading "free jazz" groups that included trumpeter Don Cherry and drummer Billy Higgins -- the one-two punch of Ornette Coleman's landmark quartet.

In his teens, Young fell under the serialist sway. At UCLA he freed up the rigid serial style using the school's large pipe organ to compose music with harmonic intervals sustained over a long time.

Out of this hands-on experience came the "Trio for Strings" in 1958, a static work that in five minutes offers just four notes. These five minutes, however, opened up a new realm of possibilities for Young and the so-called "minimalists" he influenced -- Terry Riley, Steve Reich and Philip Glass.

Throughout the '60s Young remained at the forefront of the avant-garde as a composer and performer. Having resettled in New York, he became a vital part of the art-stretching Fluxus movement with John Cage, Henry Flint and Yoko Ono, among others. He wrote a series of concept works, one of which asks the performer to release a butterfly into the audience. Another has a pianist offering a meal of hay and water to his Steinway. This piece ends when the piano either dines or declines. Young likens these efforts to haiku -- "beautiful short statements."

Since the mid-'60s, music made of sounds has been his business, from using sine wave generators to create background drones to the formation of the Theater of Eternal Music, an on-again, off-again group that tests Young's ideas in a theoretically eternal piece, "The Tortoise, His Dreams and Journey" (John Cale on electric viola was a member before he rocked out in the Velvet Underground).

The culmination of his activities were the "Dream Houses" -- controlled environments, where atop the drones, musicians improvised instrumental and vocal lines amid lights and visuals devised by artist Marian Zazeela, Young's wife.

His most powerful work to date is "The Well-Tuned Piano" (1964), whose title is a takeoff on J.S. Bach's "The Well-Tempered Clavier." Young's piece, with its improvised melodies and crashing chords, is designed to be played on a piano retuned to conform to the harmonic series. This tuning, known as "just intonation," united eastern and western theories.

Since 1970, he has studied Indian classical music with Pandit Pran Nath, passing his mentor's lessons along to his own students. His public performances have been sporadic; recordings consist of two out-of-print discs, though he's negotiating a deal to release a five-hour version of "The Well-Tuned Piano."

Yet mention the word "minimalism" and Young is quickly cited as the father. He's not exactly a proud papa. "My work really covers many more areas of sounds; it is more than 'minimalism.' " Rhythm is the major area where Young and the "pulse music" minimalists differ. "You can dance to my pieces if you're Merce Cunningham," he says, "but they don't make disco music nearly as well as my good friend Terry Riley, or as Steve Reich, or as Phil Glass."

La Monte Young wouldn't have his art any other way. His goals are beyond. Eternity in music, for instance. He notes its relation to the Kennedy Center premiere. "There is the bigger concept that the piece goes on forever, and that the players will be picking up the silence from a previous performance" (namely, a private concert given last year to celebrate Young's 49th birthday).

Long after the final note is sounded tomorrow evening, a new beginning will await in silence, as Young's music evolves toward infinity.