First performed by the New York Philharmonic last November and introduced to this country at Snape Maltings by the London Philharmonic under the composer, Thomas Adès's America (A Prophecy) is subtitled "message for the millennium". But just what that message contains is a bit obscure. On the one hand this setting of Mayan prophecies and Spanish texts (for soprano and orchestra with optional chorus) is a chilling reminder of the civilisations that were wiped out so that the brave new world of America could be founded. The soloist sings of the invaders who will come from the east, destroy their cities, and who will "burn all the land/burn all the sky". On the other hand, in the numbed and threatening lament of the second part, it seems to suggest that the nation that supplanted those endemic peoples is now intent on destroying its own world.

Yet Adès's music doesn't really offer a clinching judgment on either. There are, characteristically, some arresting sonorities - textures cleaved between high treble and lowest bass, luminous chords that materialise out of nowhere, madly tangled passages for the full orchestra threaded through with bold brass lines - but also material that seems strangely neutral, as if leaving the text to fend for itself. Obsessive Janacek-like work in the opening pages, as the scene is set for the soloist's first entry, is suddenly blown away by an eruption of diatonic brass (representing Christian triumphalism), which has the dislocating effect of one of Charles Ives's collages; while in the second part, the soprano's bleak message is haloed in shifting, wispy tendrils of melody.

The vocal writing itself (authoritatively delivered here by Janice Watson) moves in smooth, regular lines, aimed, presumably, at ensuring that the words come across. But they don't, and that failure to articulate the text fully, to give it a pertinent dramatic context, is the disappointment with America. The question of what all this invention is for never receives a convincing answer.