This weekend, Dublin is celebrating the work of Arnold Schoenberg, the modernist composer who took upon himself the burden of musical history, writes Michael Dervan

How often have you heard a classical music audience expressing its displeasure in full flight? It's not a very frequent occurrence these days, but it does happen. And when it does, it's electrifying. It's in the opera house that you're probably most likely to hear it. At the celebrated Pierre Boulez and Patrice Chereau Ring in Bayreuth in the 1970s, it almost became one of the attractions of the production.

People usually protest so vociferously only about things that matter to them. And music was certainly something that mattered in the Vienna of 100 years ago. One of the men who was to have the toughest of battles with the Viennese public was Arnold Schoenberg, who took upon himself the burden of musical history by consciously bringing the developments of the late 19th century to their logical conclusion and beyond.

Schoenberg, who was born in 1874, entered a musical world where the flames of ideological conflict between the supporters of Brahms on the one hand and Wagner on the other were still very much alive. Essentially self-taught as a composer, Schoenberg built on the achievements of both men, marrying the boundary-stretching chromaticism of Wagner's harmonic language with the obsessively intricate motivic workings that Brahms carried out within more classical forms.

The influences of Brahms and Wagner can be heard clearly in what is now the most frequently heard of Schoenberg's larger works, the remarkably intense string sextet Verklärte Nacht (Transfigured Night), completed in 1899 but not performed until 1903. It's easy to forget how much of the music of the time was considered shocking not only by contemporary audiences but also by fellow composers.

Richard Strauss seems to have drawn taunts wherever he went. The great pianist Arthur Rubinstein was hissed for playing Debussy in Warsaw in 1904. And the rioting that broke out over Schoenberg's music was on occasion serious enough to warrant the attention of the police. But Schoenberg was nothing if not determined. He was supported by Mahler (who tried to stop a disgruntled member of the audience leaving the premiere of Schoenberg's First String Quartet) and won the approval of Strauss - the two men met when Schoenberg was employed as a copyist, working for Strauss's publisher.

Strauss's great operas Salome and Elektra, which premiered in 1905 and 1909, reached into regions of musical expression from which the composer then retreated. Schoenberg's Second String Quartet, of 1908, with its added soprano voice prophetically proclaiming, "I feel air from another planet", was a different sort of turning point. The anchoring force of tonality, that sense of key centre that had served composers for centuries, was finally abandoned.

And, rather than go back, Schoenberg went boldly on in the works that followed, into a region where many of the familiar rules no longer applied. One of the most exciting eras of 20th-century music was launched.

For Schoenberg and the two men most closely associated with him, his pupils Alban Berg and Anton Webern, it was a period of unremitting challenge. "The only explanation for Schoenberg's surefootedness amid the boundless immensities of his new musical realm is that he moulded this music as if obeying the compulsive dictates of his inner visions," wrote the Swiss critic Willi Schuh of Schoenberg's monodrama Erwartung (Expectation), a disturbed and disturbing inner monologue of a woman who encounters the dead body of the lover she has gone to meet in a forest at night.

The brave new world yielded a series of masterpieces, among them Schoenberg's surreal Pierrot Lunaire, an early example of what we would now call music theatre, and a work that attempted to establish a new vocalism that was neither speech nor song, but with characteristics of both. Webern cultivated an extraordinarily compressed, aphoristic style, compacting, as it were, worlds of expression into small gestures - the entire output to which he gave opus numbers fits comfortably on three CDs. The more romantically inclined Berg produced Wozzeck, arguably the greatest opera of the 20th century, and certainly the greatest opera to surface in what came to be known, much to Schoenberg's annoyance, as atonal musical style.

The difficulties Schoenberg experienced with audiences and critics led him to found the Society for Private Musical Performances, a body that aimed to showcase modern music out of the glare of publicity, in "clear, well- rehearsed performances", with frequent repeats of works and in a context where the prohibitions included guests, applause and reviews. The first programme, on December 29th, 1918, consisted of Scriabin, Debussy and Mahler (the Seventh Symphony, arranged for piano duet).

Max Reger, now best remembered for his organ music, featured heavily. And ideological opponents of the Second Viennese School, Hans Pfitzner and Franz Schmidt among them, jostled with music that ran the gamut from conservative to cutting edge. The society mounted 113 programmes before it ceased activity, in December 1921.

"In composing," Schoenberg once wrote, "my decisions are guided solely by what I sense: my sense of form. This it is that tells me what I must write; everything else is ruled out. Each chord I introduce is the result of a compulsion; a compulsion exerted by my need for expression, but perhaps also the compulsion exerted by a remorseless, if unconscious, logic in the harmonic construction."

But Schoenberg longed for a way to bring his composing under conscious control. And in 1921 he told his pupil Josef Rufer, apparently without irony, "I have made a discovery thanks to which the supremacy of German music is ensured for the next 100 years."

The 12-tone technique he invented allowed the creation of an entire work from a single set of notes, a specific ordering of the 12 notes of the chromatic scale. A lot of hot air has been blown over the artificiality of Schoenberg's new method. In truth, it might best be likened to the artifice of metre in poetry.

It's unlikely that many people do that sort of thing by instinct rather than imitation, yet it can become ingrained enough to become second nature. And the expressive range of the technique is well attested to by the diversity of style manifested by the three men whose names are most closely associated with it.

Just think of the rigorously sculpted formal balances of Webern's Variations, Op 27, for piano, the garish colours and often tortured language of Berg's second opera, Lulu, and the sometimes otherworldly expressionism of Schoenberg's late String Trio, a work that, the composer confided to one of his neighbours, the writer Thomas Mann, reflected a near-death experience in hospital, with reminiscences as specific as the hypodermic needle and the male nurse who'd been caring for him.

The challenges of the music of the Second Viennese School have less to do with the 12-tone technique than with other characteristics of its compositions. From their earliest days, its adherents wrote music that is unusually content-rich. There's an awful lot to digest.

It can hardly be regarded as surprising, then, that when rebellion was finally mounted against the post-war serialists who built on the foundations Schoenberg had laid, it should have come from the minimalists, whose music ditched the sort of content Schoenberg prized in favour of stretched-out processes using relatively simple material.

Schoenberg himself is a man of great paradoxes. He was superstitious enough about the number 13 to change a biblical spelling and title his largest, but never-completed, opera Moses Und Aron, so it wouldn't have 13 letters. In his youth he was an active painter and exhibited with Kandinsky's Blaue Reiter group. He seemed almost immune to the hostility his music generated, yet in his years in Los Angeles he gave his son Lawrence a dime for every Schoenberg broadcast he tracked down in published radio listings.

He played tennis with George Gershwin but refused him lessons, saying he would only make him a second-rate Schoenberg when he was already such a good Gershwin. And he once declared there was plenty of good music to be written in the key of C, and in 1934 wrote a suite in G, for a college orchestra, giving in, as he did from time to time, to what he described as the "always vigorous" longing to return to the older style.

Schoenberg lived to be 76, dying in 1951. Berg died in 1935, at the age of 50, from blood poisoning following an insect bite. Webern was 61 when, taking an outdoor smoke during a curfew, he was shot by a US soldier, in 1945. Had these men lived into the adventurous spirit of the 1950s avant-garde, the face of music would have been very different. The major recent worldwide celebration of Schoenberg's work took place last year, marking the 50th anniversary of his death.

The National Symphony Orchestra's Schoenberg, Berg & Webern: Evolution Or Revolution? weekend, with its mixture of talks, concerts and an exhibition, brings together works from all periods of the composers' lives, including works by Schoenberg and Berg that have never been heard in Ireland. With a selection of music that stretches back into the 19th century, the offerings seem set to test the remark that Virgil Thomson made of Schoenberg in 1944: "His music is still the modernest modern music that exists."

Schoenberg, Berg & Webern: Evolution Or Revolution? runs from tomorrow until Sunday, with events at the National Concert Hall and the National Gallery of Ireland. Details from 01-4170000