Music for the generation which spaced out to Pink Floyd

Composer Jonathan Harvey's new work, premiered in a Prom this week, could gain him a cult following

Imagine a concert, given by the BBC Symphony Orchestra with several exotic percussion instruments, female chorus and semi-chorus. A wizard then shakes some magic into proceedings: he doesn't conjure any extra musicians or add exotic instruments, but somehow he does something to add several layers to the tapestry of sound created by the musicians, and to send a disembodied voice journeying around the hall. Jonathan Harvey is that soft-voiced magician whose new work, Mothers Shall Not Cry, will be given its world prÿmiere at this Wednesday's Prom.

Imagine a concert, given by the BBC Symphony Orchestra with several exotic percussion instruments, female chorus and semi-chorus. A wizard then shakes some magic into proceedings: he doesn't conjure any extra musicians or add exotic instruments, but somehow he does something to add several layers to the tapestry of sound created by the musicians, and to send a disembodied voice journeying around the hall. Jonathan Harvey is that soft-voiced magician whose new work, Mothers Shall Not Cry, will be given its world prÿmiere at this Wednesday's Prom.

Harvey's music could well gain a cult following amongst the generation which spaced out to the wilder reaches of Pink Floyd or the more surreal moments of John Williams's score for Raiders of the Lost Ark. Orchestral and instrumental colours seem to "morph" (Harvey's own term) before our ears into strange, other-worldly sounds: in one of his most spell-binding works, One Evening, an Indian tabla rhythm speeds up and rise in pitch, as if the recording were being accelerated, until it actually transforms into a rising musical note which swoops from one speaker to another.

Such fluid transformations are part of Harvey's usual armoury of musical effects gained through his work in the avant-garde electronic studios used by Boulez and Stockhausen. There he analysed instrumental timbres, so discovering the constituent "spectral" elements of each sound. Through an alchemy beyond the basic cookery of orchestration, his music can recombine or blend from one instrumental sound to another, or seamlessly enter the alien tones of his electronic music.

Mothers is Harvey's third Proms commission, following Madonna of Winter and Spring (1986) for large symphony orchestra and electronics, and a Percussion Concerto for Evelyn Glennie in 1997. That both audience and critics gave a warm response to these works seems to have encouraged him to write his most ambitious piece yet - certainly in terms of the forces used and in using virtually every part of the Royal Albert Hall in his dramatic conception. But when asked what he has learnt from his previous experiences of writing for the Hall, Harvey is quite modest: "I don't hope for very sensational sound movement - I've learnt that: it's not like a dry, very precise hall where you can follow everything, every part of the sound."

Although Harvey's music has been described as spiritual, its fluid colours and dramatic qualities are leagues away from the aural baths of Pärt or Tavener's choral music. Nor does it sit comfortably with the dark, often bitter poignancy of James MacMillan's work - albeit both composers contributed to a forum held earlier this year at Sussex University, "The New Metaphysical Art". Harvey's latest work might also be seen as a move towards MacMillan's politically committed world, as Mothers Shall Not Cry commemorates the victims of atrocities committed in the past century. But while MacMillan might have presented a bleak confrontation of barbarism with God-like innocence, Harvey is more concerned with resolution, or, as he prefers to call it, with unity: "I like to unify" Harvey explains; "not an easy unity, but a unity which is rich and complex."

Certainly the opening of Mothers is strikingly apposite. We have grown used to daunting lists of the slaughtered carved in stone or inscribed on memorial plaques, but it is not often such a list appears dramatically set in a musical work: some of the names are of people killed or murdered only last year. The title Mothers Shall Not Cry itself was taken from an Amnesty International banner that appeared in an demonstration held in Turkey. "It was a group of Taiwanese women", recalls Harvey; "[they] had their own disappeared sons in an incident some 20 years ago concerning the Chinese... I just thought that was so fitting: it has the idea about mothers, and it has this idea of hope for a day when this doesn't happen. Mothers are, in a way, the key to the work."

Harvey's concern with the feminine perspective is evident from a short but dramatic choral piece written in 1995 for St Paul's Cathedral Choir, Dum transisset sabbatum - "which I actually feel is important to me", he confessed when I interviewed him last year. It describes the two Marys and Salome going to the sepulchre to anoint Jesus at dawn, and their dramatic discovery of his missing body. "It's so wonderful", Harvey told me then, "because women play so little part in Bible events, and that is a very important theme for me."

Evidently for Harvey that's as true today: "It's become more present," he says, "the idea that the patriarchy has not been very successful somehow; well, to put it more positively, that the values of the mother and so on are very universal and yet not given their proper respect in many societies." Mothers is his fullest development to date of this theme. Apart from the opening chorus, its main protagonists are a soprano soloist who, Harvey's programme note explains, represents the "Sacred Feminine", and, as her counterpole, a "noble" warrior played by a tenor. The soprano's texts are taken from women saints or writers "from the great religious traditions", a blend typical of Harvey who, though now a Buddhist, was a devout Christian as a boy: "I don't particularly lose any of my love of Christianity or any other thing that I've come into contact with in my life" he explains; "I tend not to reject them but to enrich them with other areas."

The warrior's texts, by contrast, while articulate are in a made-up "unknown" language: "I think that's a symbol I would like to leave fairly undefined." says Harvey; "This warrior's a certain kind of person, searching but so immured in his systems he doesn't know how to get out of them although he wants to. I suppose that's about as much as I can say." In an interview, maybe, but no doubt Harvey's music will have plenty more to say on the night.

Jonathan Harvey's Percussion Concerto and 'Madonna of Winter and Spring' are released on Nimbus NI 5649; Mothers Shall Not Cry': Royal Albert Hall, SW7 (020 7589 8212), on Wednesday and broadcast live on Radio 3, 7.30pm