Other Trumpets Fascinating electro-acoustic collaborations - heard by MALCOLM TATTERSALL '... individual works are challenging listening but stunningly achieved.'

The idea of a 'concept album' may be more common in the pop world than in classical music but it is the simplest way of interpreting Other Presences. Jonathan Harvey composed the title track and then invited seven other composers to create their own pieces around one element of it, somewhat as Diabelli invited his fellow Viennese composers to write variations on his waltz. Technology has changed, however: Harvey didn't pass around a piece of manuscript but an audio recording.

Jonathan Harvey is one of England's senior composers. Born in 1939, he studied at Cambridge, was influenced by Babbit and Stockhausen, worked at IRCAM in the 1980s and is now Visiting Professor of Music at Oxford and Honorary Professor at Sussex University. The composers he invited to participate in this project are mostly younger, mostly British by birth or residence, and work in the experimental side of popular music and/or the Stockhausen/Boulez electro-acoustic tradition. Their collaborative disc is a fascinating window onto the possibilities of modern audio technologies.

Harvey explains the process succinctly in the CD booklet:

'My composition was inspired by Tibetan ceremonies I have witnessed [and] by the marvellous trumpet playing of Markus Stockhausen. He tours around with a live electronics system which he manipulates himself while playing. It consists, in the present work, of looping the sounds he plays, harmonisations of his sounds and spatialisation. The many loops appear in the four loudspeakers placed in the four corners of the concert hall, so that he is, so to speak, multiplied into many "other presences", reflecting the self in the world.'

Harvey continues, 'The solo trumpet line, without loops or electronic treatment, was sent to the composers who agreed to make "remixes". They were free to do what they wanted as long as no new sounds were added and a certain time limit was observed. So, in contrast to my live piece, everything here is pre-recorded and worked on in the studio.'

Diabelli's audience had at least an easily recognisable tune and harmonic framework to anchor their attention from one variation to the next, but Harvey's Other Presences is quite abstract and the derivative works use scraps of it as they like. Kaffe Matthews, for instance, chose to 'pull out the small muted trumpet extract ... and blow it up and out and forwards,' making a series of gradually expanding bubbles of sound:

Lawrence Casserley processes and re-processes the tape to lose the original trumpet sounds almost completely, leaving only quiet ghostly resonances, while Gilbert Nouno chose to retain far more of Harvey's concept, layering the audio in the studio in much the same way Stockhausen did in performance. Evelyn Ficarra's textures are also similar to the original but more fragmented and more heavily manipulated than Nouno's:

Daniel Biro 'focuses on the rhythmic possibilities of the staccato trumpet parts of the original', with a nod to Miles Davis, while the composer's daughter Anna creates by far the most romantic remix:

Finally, John Palmer stretches the project brief to its limits by choosing to 'manipulate the spectral characteristics of single sounds in order to create new sounds and create a new music from scratch.'

Each of the individual pieces is satisfying but the disc as a whole is less so. Listening to nearly an hour of nothing but trumpet tone -- however altered -- before the beginning of Palmer's piece tests the attention quite severely; and then Palmer alters the original material so radically that one would hardly know a trumpet existed in his source material, but that means his piece doesn't close the circle as satisfyingly as Nouno's work might have done.

Production values, both aural and visual, are excellent except that the CD booklet says nothing whatsoever about the composers. The pointers to their websites are presumably intended to fill that gap with continually updated information, but Sargasso may have unwittingly deprived many first-time listeners of a context for what they are hearing by putting the information out of easy reach.

But that is a small fault. On the whole, the individual works are challenging but stunningly achieved, and will reward listeners prepared to make the effort.