Louis Andriessen is without a doubt the bestknown of living Dutch composers. His work has been taken up by the Nonesuch label, home of the fashionable Kronos Quartet, and issuers of the chart-topping version of Gorecki's Third Symphony. His collaborators in recent years have included Peter Greenaway (on the film M Is For Man, Music, Mozart and the "horse opera" Rosa), and Robert Wilson (who directed the music theatre work De Materie - Matter). He has long been an influential teacher and, for even longer, an outspoken agitprop-style advocate of change and reform.

He was born into a musical family in 1939. Today, his listing in the CD catalogue is preceded by the names of his father Hendrik and brother Juriaan, both of whom were influential in his early musical life. His father's taste leaned towards France rather than Germany and to this day Andriessen finds most of the 19thcentury German Romantic repertoire 1840 to 1900 a closed book. "I have a sort of comprehension of it, and respect, especially for Brahms. Very structural," he says, with a smile. "I still think that Chausson is a much more interesting composer than Wagner. I give exactly this example, because Chausson was one of the few French who were really strongly influenced by Wagner. Other French composers have their doubts about Chausson. I sometimes like Wagner when there is done something with it which makes it totally different." With his 60th birthday just two years away, he feels he still has time to come to terms with German Romanticism. He recently heard Schumann's piece Davidsbundlertanze for the first time, played by the American pianist Charles Rosen, "as if he'd just heard it from Schumann. Very nice". He found, he says, "wonderful things" in the music. Yet, while relishing the pleasure of this new experience, he still expresses reservations about Schumann and what he calls the "two disease"; the way that almost every bar is repeated immediately. Andriessen's strong personal affinities fall neatly clear of the closed-book German period - J.S. and C.P.E. Bach on the one side (interestingly, a father and son pair), and Stravinsky (about whom he has written a book) on the other. Away from family connections he was a pupil of Luciano Berio, and as a young composer in the 1960s he allied himself to the avant-garde trends of the day. He was among the composers involved in the Holland Festival's collaborative "morality" Recon- struction of 1969, colourfully described by Nicolas Slonimsky as "a brogdingnagian anti-imperialist pasquinade . . . denouncing Yankee incursions into bucolically vulnerable Latin American countries". He was involved in the protests at Bernard Haitink's appointment as principal conductor of Amsterdam's Concertgebouw Orchestra. The composers favoured Bruno Maderna, who would have given a higher profile to contemporary music.

In the early 1970s he founded - and for a number of years played in - the ensemble De Volharding (Perseverance, named after one of his pieces), which, with a line-up of piano, trumpets, saxophones and trombones and members whose backgrounds were in jazz, was as effective in street protests or in a factory as in the concert hall. The original breadth of activity would be much more difficult now than it was 25 years ago. "Commercial industry closes more and more the entries to culture instead of opening them."

In musical terms, however, the agitation paid off handsomely. Amsterdam, with a population not much larger than Dublin's, now has around 20 contemporary music ensembles, subsidised by national and local government. De Volharding still exists, though a second Andriessen ensemble with a more exotic line-up, Hoketus (topped by two panpipes, and again named after one of his pieces) eventually splintered. Andriessen illustrates the health of the current situation by recalling that an Amsterdam performance of Stockhausen's Gruppen for three orchestras was able to take place using only the members of some of the specialised ensembles, without recourse to the membership of the Concertgebouw Orchestra (which can still - literally - play Mahler symphonies three or four times a week to packed houses).

It's often assumed that composers who moved on from serialism experienced a certain sort of disillusion. Not Andriessen. "I've never had that feeling. What happens is that, at a certain point, you have eaten what you need. Or it's like you grow out of it. Or, as we sometimes say in Dutch, `It's a past station'. There are all sorts of ways to describe the fact that you are not gripped with interest, that when you open your ears you hear other things suddenly." He instances hearing the LP of Terry Riley's minimalist milestone In C in the 1970s as a real revelation. "It was an opening of a door towards a future which was very inspiring for me. Because he combined a totally new concept of time, which had much to do with avant-garde thinking, and also with non-Western, non-developmental music. And on the other hand it had the principal of pulse, which was very typical of pop music. The idea of De Volharding around that time was also of crossing or going through borders of high and low-brow music. Nowdays I seem to try to make a point out of this problem."

Andriessen is nowadays bestknown for a series of large-scale pieces with imposing titles and subjects De Staat (The State, a setting of Plato), Mausoleum (Bakunin), De Tijd (Time, St Augustine), Snelheid (Velocity) and the four-part, evening-long De Materie (Matter, with texts ranging from the erotically-charged writing of the 13th-century poetess Hadewijch, to 17th-century shipbuilding instructions and the description of an encounter with the painter Mondrian). He's currently working on an opera on Vermeer. His typically saxophoneand brass-rich ensembles often call for electric guitars and keyboards, and he expects the sound to be amplified, not for loudness, but for balance. "Two trumpets and harp can be beautifully balanced nowdays."

The composer will be in Ireland next week for workshops and a concert by the Crash Ensemble, a new group with an especial interest in multimedia work. Composer Donnacha Dennehy, currently lecturing in music technology at TCD, and Andrew Synnott, who has conducted a number of productions for Opera Theatre Company, are the steering forces and they have drawn in the expertise of John Godfrey who, in addition to lecturing at UCC, plays in the leading amplified ensemble, Icebreaker. The group's debut programme will involve choreography (Cathy O'Kennedy), video (Hugh Reynolds) and lighting design (Paul Keogan) as well as electronics for sound.

ANDRIESSEN's more recent larger works, finished with textures which seem to polarise into arresting or exquisite, move with a tread which essays the epic. The Crash Ensemble's debut programme focuses on smaller pieces. On Jimmy Yancey is a 1973 homage to the boogiewoogie pioneer who was "the first to change the jumping, ragtime left hand into the steady beat of the blues guitar. There's also an urban side in the boogie-woogie which interested me. It's been described by somebody as the sound of the trains the boogie-woogie players heard rolling under them when they were playing in the bars in Chicago."

Andriessen's love of jazz goes back to his early teenage years and the radio stations he was then "fixated on". Until some time in his thirties or forties he much preferred to go to jazz events than to classical concerts.

The larger works, finished with textures which seem to polarise into arresting or exquisite, move with a tread which essays the epic. The TCD programme of the Crash Ensemble, a new group with an special interest in multimedia work, focuses on smaller pieces. On Jimmy Yancey is a 1973 homage to the boogiewoogie pioneer who was "the first to change the jumping, ragtime left hand into the steady beat of the blues guitar. There's also an urban side in the boogie-woogie which interested me. It's been described by somebody as the sound of the trains the boogie-woogie players heard rolling under them when they were playing in the bars in Chicago." Andriessen's love of jazz goes back to his early teenage years and the radio stations he was then "fixated on". Until sometime in his thirties or forties he much preferred to go to jazz events than to classical concerts. The score of Workers' Union (1975), "for any group of loudsounding instruments", is precisely notated in rhythm but offers only approximations for pitch. The composer's note wryly explains, "It is difficult to play in an ensemble and to remain in step, sort of like organising and carrying on political action".

Dubbelspoor (Double Track) of 1986 was written for a dance performance and is, by contrast, "very elegant, glass-like, transparent, in sound. It uses only four instruments, piano, harpsichord, glockenspiel and celesta". Andriessen expresses pleasure at the choice of pieces for the Dublin concert. "What I like is that they do sound different, and they show different sides of me. There is the nice side, and the more, I won't say aggressive, but outspoken side." And does the still outspoken composer have any difficulty seeing himself as a successful member of the establishment? He laughs. "You know who got the Nobel Prize for literature? Dario Fo. It's a much worse problem for him than for me."