Film, art, writers. Now opera is a hit for Scots

"Why opera? This is the big question," says James MacMillan, Scottish music's brightest new hope. "People outside must think composers mad to even try to continue with a tradition which could be seen as a museum culture."

At 36, MacMillan, wearing shorts, T-shirt and trainers, is anything but old-fashioned. As we sit in a cafe in Glasgow's Theatre Royal, only his manicured nails and liquid hand-movements betray a musical sensibility, and he waves them as he speaks as if orchestrating his points.

He has just written his first full-length stage work, commissioned by Scottish Opera to celebrate 50 years of the Edinburgh Festival. Ines de Castro, a piece based on John Clifford's play of the same name, premieres later this month in Edinburgh before touring to Newcastle and Glasgow. A true and bloody story set in 14th-century Portugal, it involves political tension, religious ritual and devotional love. The opera is the most important piece of MacMillan's career and one of the highlights of the International Festival.

Scottish culture is enjoying a renaissance. Irvine Welsh's Trainspottting is a cult hit worldwide, and has made its star, Ewan McGregor, a heart- throb. Scottish writers grace the pages of the New Yorker. Douglas Gordon, a Glaswegian, is tipped to win the Turner Prize and David Greig's acclaimed play, The Architect, is enjoying a second festival run.

In classical music, the scene is equally vibrant. As well as MacMillan, there is Judith Weir, Sally Beamish and John Maxwell Geddes, while Peter Maxwell Davies' move to the Orkneys and his compositional classes have had a profound effect on Scotland's young composers. But it is MacMillan who is the brightest star on the musical horizon.

"Of all his generation of British composers, he seems to be the one with the most obvious appeal to a wide audience," says Michael White, Independent on Sunday music critic. "And that's because what he writes is strong and lyrical and direct, and above all it's not afraid of being emotional. Those things strike audiences very powerfully."

MacMillan was born in the tiny Ayrshire town of Cumnock. His first composition coincided with his mastering the recorder when he was nine. He went on to form a street band with friends, and composed small piano and orchestral pieces while in his early teens. He always wanted to be a composer and enrolled to study music at Edinburgh University when he was 18.

After a traditional grounding, he took a post-graduate course in compositional studies at Durham University. A series of teaching jobs followed until, in 1988, he returned to Scotland to concentrate solely on music.

Since then his output has been prolific. He has written dozens of pieces for voice and orchestra, including three concertos: The Berserking, written for Peter Donohoe, pianist; Epiclesis, for John Wallace, trumpeter; and Veni, Veni Emmanuel, for Evelyn Glennie, the percussionist. A recording of Veni, Veni Emmanuel won the 1993 Classic CD award for contemporary music.

MacMillan is not part of any recognised school and his work is powered and inspired by a wide range of concerns. His socialism, Catholicism and belief in humanitarian causes sets him apart from his comtemporaries.

"Some composers can be completely caught up in the nuts and bolts of their craft and ignore the rest of the world," he says. "But I feel too much part of the community and of the world to be able to shut it out."

Busqueda, which includes words for eight actors, focused on Argentina's Mothers of the Disappeared; Tuireadh, a lament for the dead, is dedicated to the victims of the Piper Alpha disaster and their families; and Sowetan Spring is partly inspired by South Africa's national anthem. Strong strains of jazz, folk and Latin American music also inform his work, and his style is eclectic, dramatic, even angry.

"I love what could be described as music of the people, music which is rooted in communities," he says. "I joined the Young Communist League when I was about 14 and am an avid reader of political journalism. Isuppose I find it easier to be inspired by certain political issues."

And as the question of Scottish devolution or independence rises once again, he believes the political situation is fuelling Scotland's artistic renaissance.

"Being Scottish has influenced some of the pieces," MacMillan says. "It's up to those involved in public life and the arts to think seriously about our cultural and political situation, and about where we've come from culturally and what we are contributing. To an outsider, it can sometimes look as if a lot of Scottish artists are indulging in navel- gazing; but it's an important time for us to make our own analysis of who we are, what we've been and where we might go, rather than have it all mapped out for us."

MacMillan's first major operatic work could project him to the heights of the international scene. But James, or Jimmy, as he introduces himself, would rather see the world in terms of his vocation than a career.

"Ines de Castro is the most complex and the biggest piece of work I have written," he says. "It has expanded my vocabulary and the emotional range. Every piece is a step towards maturation of style and personality."

Scottish opera used to be an oxymoron. With James MacMillan's exciting next work, opera in Scotland could stop being an archaic import and become instead a vibrant cultural export.