Orphée, Linbury Studio, Royal Opera, London

Is it a sign of extreme caution, extreme conservatism or plainly being out of touch? It seems incredible that, despite huge audiences for the type of work, the Royal Opera House has not mounted an opera by one of the American minimalist composers until now. Amazing that John Adams's Nixon in China or The Death of Klinghoffer, so potent in the annals of contemporary work, have failed to be presented at the ROH.

Is it a sign of extreme caution, extreme conservatism or plainly being out of touch? It seems incredible that, despite huge audiences for the type of work, the Royal Opera House has not mounted an opera by one of the American minimalist composers until now. Amazing that John Adams's Nixon in China or The Death of Klinghoffer, so potent in the annals of contemporary work, have failed to be presented at the ROH.

Even more regrettable that Philip Glass's Einstein on the Beach, Satyagraha, and Akhnaten , operas that paved the way to Adams's work, have not even been sniffed at by the ROH. And yet, the normal reception of these works around the world has been sell-out houses. So it is somewhat shameful that, more than a dozen years late, London gets a UK premiere of a relatively elderly work by a relatively elderly composer, not in the main house, but in the studio black box, The Linbury.

Orphée is Philip Glass's eleventh opera; it is a chamber work. It may have been in reaction to The Voyage commissioned by New York's Metropolitan Opera in 1992 - where Glass pulled out every stop available to a major opera house - that in that same year he turned to the relative intimacy of Jean Cocteau.

Glass set three of Cocteau's greatest films - Orphée, La Belle et la Bête , and Les Enfants Terribles. No doubt he identified with Cocteau: "a man resented not only for his success in many different media but for his sheer fluency, a man who saw himself as a misunderstood genius". Glass's audience is massive and loyal but he has been vilified by composers and critics. Setting Cocteau could be interpreted as Glass's reflection on the Humpty Dumpty world of composition, where audience opinion doesn't count. But it also relates to tragic events in his life: his young wife had died the previous year.

Orpheus in opera is as old as opera itself. But Cocteau's take is elaborate and Glass's take on Cocteau more convoluted still. Glass maintains Cocteau's French text and surtitles are provided. But Es Devlin's ambitious rising and falling diagonal gangplank occasionally masks the titles. Action takes place on several levels - but could those seated further back see into Hades? The look - dry-ice, shiny surfaces, hi-tech neon, and some elaborate costumes - invokes both Kafka and Star Wars.

Glass's music follows his usual routine - burbling arpeggios, chugging bass, rhythmic accompanimental figures - over which the singers lyrically intone their words. Glass trails operatic references - Gluck's "Dance of the Blessed Spirits" or Don Giovanni's descent into hell (Orphée has a particularly nasty death) - but the music does not signify character development. At its best, Glass's music is touchingly expressive - perhaps because so much is in the minor mode. But banality lurks nearby.

The ROH has taken a leap but it's time for more significant minimalist work.