A critic once called composer John Adams the Hamlet of contemporary classical music, accusing him of not being able to make up his mind and settle on a specific musical style. It is a charge with which the Berkeley-based Adams is all too familiar. "Recently," he explains, "I read another review that said, 'Well, he started as a minimalist, then he was a neoromantic, then he became an opera composer, and then he flirted with atonality -- and now I don't know what the hell he's doing.' And I thought, Is this a criticism? Does this mean that the work is not important?"

For the answer to that question, look to The John Adams Earbox, a ten-CD set recently released by Nonesuch in celebration of the composer's 50th birthday. Spanning more than two decades of his musical output, the set features his famous modern operas Nixon in China and The Death of Klinghoffer, the world-premiere recording of Slonimsky's Earbox (whence the set took its name), as well as the first Nonesuch recordings of several of Adams's more popular works. With the wide range of material presented -- piano and electronic music, orchestral works, chamber music, a violin concerto, operas, and even a pop musical -- Earbox has the potential either to further confound critics desperately trying to pin a label on the composer, or to clear up the many misconceptions swirling around his eclectic-sounding oeuvre.

Even though his name is regularly lumped together with Steve Reich and Philip Glass, Adams, from the start of his career in San Francisco in the early '70s, has taken issue with some of the basic tenets of minimalism. "I don't want to sound like a crabby old critic," says the usually affable composer, "but I felt that as pleasurable as it was, in most cases there was simply not enough to sustain my intellectual or even my sensualist commitment. Educated, highly sensitized musical ears simply demand more from the musical experience than putting together some attractive sounds and letting them go through their changes. That's where I really part company with the minimalist aesthetic."

While the early compositions on Adams's box set, such as Shaker Loops (1978) and Harmonium (1980), may at first strike the listener as basic minimalist exercises, they actually are works of far greater complexity. Adams's trademark rippling, wavelike patterns are there, but so too are unpredictable, almost violent shifts in mood. Tinged with the orchestral colors and harmonies of late romanticism, these compositions marked the beginning of Adams's mature style, one that stands in fierce opposition to the cool conceptualism of the modernist movement.

As Adams gained recognition in the early '80s during his tenure as composer-in-residence at the San Francisco Symphony, criticism from the establishment followed. Instead of being pegged as a minimalist, Adams was now dubbed a neoromantic. Works like Grand Pianola Music (1982), with its shameless, almost gaudy tunefulness, were seen as a flagrant retreat from the aesthetics of modernism. "There was a whole article devoted to me in the New Republic by Edward Rothstein," Adams remembers. "And it was my first experience of someone roasting me. The diatribe was essentially that I'd taken this pristine, fresh form and just corrupted it." He smiles. "It amazed me that I would have the power and the poison at such a young age to corrupt something. But that was a common criticism of me back in the mid-'80s."

Despite such attacks, Adams's popularity among audiences and orchestras grew. Within his first ten years of writing for orchestra, he became one of the most frequently performed living American composers; his accessible, energized compositions became a breath of fresh air for performers and listeners fed up with Western art music. But with Adams's foray into the world of opera, new criticisms loomed on the horizon.

Nixon in China (1987) and The Death of Klinghoffer (1991) marked radical departures from standard operatic format, taking events from recent cultural and political history and placing them in a nineteenth-century, grand opera framework. Both works were quickly labeled "docu-operas," with some dismissing them as operatic pop art before they premiered. But in spite of the naysayers, Nixon drew a good deal of positive press, winning a 1989 Grammy Award and being hailed by Time magazine as one of the ten most important recordings of the decade.

Klinghoffer, sadly, did not fare as well. With its politically charged, ripped-from-the-headlines subject matter (the 1984 hijacking of the Italian cruise ship Achille Lauro by Palestinian terrorists, and the subsequent murder of a wheelchair-bound Jewish passenger, Leon Klinghoffer), audiences and critics alike seemed unable to separate fact from fiction, actual event from artistic expression. The work was picketed, criticized, condemned for having little or no artistic value. It has enjoyed several productions in Europe over the years, but it hasn't been staged in the United States since 1992, when it was performed in San Francisco.