Voxygen, Talvin Singh's commission for the English National Opera, is not a formal composition, but more a collection of pieces featuring the master tabla player's favourite singers. What we hear are a succession of vocal pieces, some of which float over busy electronica, all of which are stamped with Singh's personality. He jumps from tablas to laptop to keyboards to harmonium and any number of percussion and drum-triggering devices.

But a charismatic performance is not enough: most of Singh's numbers require extensive improvisation over attractive, repetitive, often asymmetric patterns. Here, the ensemble sound is not sufficiently immersive to generate the trance-like state you might achieve at a club or festival, nor is the content rich enough to provide the engagement of a recital.

So what we get is that familiar beast, the "big commission": well intended; well funded (sponsored by O2 with a title that sounds suspiciously like "oxygen"); well marketed; and well co-ordinated, with singers from Italy (Francesca Cassio), France (Ravi Prasad), the US (Iranian-born Sussan Deyhim) and India (the venerable Ustad Rahim Fahimuddin Khan Dagar). Yet Voxygen ends up being smaller than the sum of its parts. (Though Patricia Rozario, who took part in Monday's premiere, was not involved in the performance I heard.) To combine electronica, complex acoustic instruments and a diverse array of vocal timbres requires highly sophisticated sound diffusion. Here, the poor sound mix makes each singer's task harder, while a battery of keyboards and computers ends up sounding like dull drum machines.

Nevertheless, it was a treat to hear Deyhim's voice - a remarkable instrument - and a privilege to hear the opening "blessing": a totally acoustic performance by Dagar, enhanced by Singh's peerless tabla-playing.