Call composer Steve Reich a "minimalist" and he doesn't get angry; he gets patient.

At 49, with more than a dozen compositions listed in the Schwann record catalogue and his latest -- "The Desert Music" -- holding at No. 10 on Billboard's most recent classical chart, Reich can afford to tolerate simple-minded labels. His musical identity is established, and lately it is sounding more and more symphonic. His schedule is crowded with commissions two or three years ahead, including works for the symphony orchestras of St. Louis and San Francisco. He wants to postpone a piece for the London Sinfonietta for a year or two because "it's going to be too much orchestral stuff; I want to do something that's going to sort of clear out the air."

But he still earns more as a performer than as a composer. "You don't make it on commissions," he says, "unless you crank out one a week. I couldn't keep my wife and my 7-year-old son alive on commissions." So he will be performing in the Washington premiere of "Desert Music" tonight at the Kennedy Center and the world premieres of two new works next week at New York's Lincoln Center.

In any case, Reich no longer has to drive a cab (as he did in the 1960s) to pay the rent. As for the minimalist tag, he has a degree in philosophy (with honors) from Cornell, so he knows how to be philosophical.

He sounds philosophically resigned when he talks about the name he is called: "Debussy, Ravel, Satie, Koechlin are impressionists; Scho nberg, Webern and Berg are expressionists; and Reich, Glass, Riley and La Monte Young are minimalists. All those words come from visual arts, and all those words were not enjoyed by the composers to whom they were applied, and all those composers had precisely nothing to say about whether those descriptive terms were used or not.

"Scho nberg wanted his music to be called 'pantonal,' and the world said, 'That's nice, Arnold; goodbye and good luck. That ain't your job.' And that's what it comes down to; it's really for journalists, music historians . . . and as a journalistic, music-historical term I think minimalism is going to stick. Frankly, given the options of 'trance music' or 'hypnotic music,' maybe we got off easy."

Minimalism, in case you have been listening to something else for the last 10 or 15 years, is a kind of music, usually performed by small groups, that emphasizes repetition of simple motifs with static harmonies and very small, slowly developing changes in melody, rhythm, instrumentation or synchronization. Its composers are usually influenced by nonwestern systems; its esteemed ancestors are Eric Satie and John Cage, its founding father is La Monte Young and its most visible exponents are Reich, Philip Glass, Terry Riley and, most recently, the up-and-coming John Adams.

This very basic idiom communicates simply and directly with audiences, so minimalism may be considered a part of the larger phenomenon of neo-Romanticism. It definitely represents a revolt against the academic flavor that dominated new music for a long time after World War II. And in this it is so successful that you could argue forever about whether it is popular or classical.

In Reich's mind, there is no question. "I don't think I'm writing pop music," he says. "One thing people should be able to hear is that the person who wrote 'Desert Music' seems to be the same one who wrote 'Drumming,' even though they're very different."

One difference is that his music has been getting progressively less minimal since 1971, when he began "to look to expand my vocabulary in specifically western ways, which means harmonically and orchestrationally."

As far as the minimal instrumentation is concerned (three to five players when his ensemble began), that was a matter of economics, not choice.

"When I started to write 'Drumming' in 1971," he says, "I began to realize, to my horror, that I needed nine percussionists and singers to make this thing happen. There was a real kind of growing pain . . . and then, when I wrote 'Music for 18 Musicians,' I thought, 'Oh, gosh!' "

Reich finds it slightly ridiculous for Americans to imitate the styles of "ethnic composers" from war-ravaged Europe. "Karlheinz Stockhausen and Luciano Berio are giving a good, honest taste of what it was like to be in bombed-out Cologne and post-World War II Italy," he says. "But people living in California and New York City amidst tail fins, McDonald's, bebop and rock and roll -- to pretend that they are going to give us the dark-brown flavor of 1912 'Pierrot Lunaire' or 1946 Cologne -- forget it; it's a lie.

"Music comes from a time and place . . . It's there. And it's not there consciously, waving a flag; it's in your bones. What we're talking about is what academic music has always done; it has fed on some prior music which was a real music coming from a real situation, made it entirely insular, totally artificial, and passed it on as high art. I think that while the people we have discussed will survive, those who have imitated them in another country, another time, are the same as the Horatio Parkers who thought Ives was crazy."

"The Desert Music" is Reich's first work completely thought out in orchestral terms, and only his second with a text -- the first was "Tehillim," which used words from the Hebrew text of the Book of Psalms. Thematically, "The Desert Music" is rooted in the reality of the atomic era, with a text taken from poems written by William Carlos Williams at the dawn of that era. A key text, repeated twice at the center of the music's archlike structure, warns that "man has survived hitherto because he was too ignorant to know how to realize his wishes. Now that he can realize them, he must either change them or perish."

There's nothing minimal about that.