Pop: Live Reviews: Blood on the Fields/ Wynton Marsalis Barbican Hall, London

Like its subject, slavery, Blood on the Fields lasted an awful long time. The songs were great, Cassandra Wilson was sublime and there was some incredible music, but nothing moved one quite so much as the promise of release from bondage. The London performance was the final night of a tour that began in January, and it felt like it. The band looked tired, poor old John Hendricks - who is 75 - was puffed out by the time he got to the mike for each of his solo-spots, and while conductor and bandleader Marsalis tried to inject vigour into the proceedings, some of his charges were clearly running on empty. Though not quite clocking up the expected three hours, the performances seemed much, much longer.

Part of the blame may have lain with the Barbican stage, whose deep apron seemed to create a virtual glass curtain between performers and audience. Add to this a total lack of design - undifferentiated white lighting, with almost as much light in the hall as on stage - and the result was uncomfortably like watching a rehearsal. Though you can argue that the piece stands or falls as music and nothing but, Blood on the Fields is really a collection of songs and as such there needed to be at least a suggestion of stage business to lead us from one to another. Any sense of mystery was undercut by the too-visible figure of a hippie sound engineer sat at a primitively camouflaged desk at far stage left, like a refugee from a Grateful Dead concert. But at least the Dead would have had a few lighting cues to play with. Having failed to establish a stage presence at the beginning, the show struggled to capture the hearts of an audience who were just waiting to be invited inside.

This may be too hard, however. Much of the music was glorious, and Wycliffe Gordon's trombone trumpetings, Rodney Whittaker's steadfast double-bass patterns, and Herlin Riley's heroic drumming were outstanding. While Marsali's scoring for the orchestra - heavier on the brass than the reeds - was relatively straightforward, with no real underlying structure, there were many occasions when the collective oomph of the enterprise took your breath away with sheer delight at the majestic bluesiness of it all. And Cassandra Wilson was thrillingly good, confirming her status as the best female jazz singer there is. The diminutive Miles Griffith was almost equally adept, and, in retrospect, the vocals, the songs, and the words were enough to redeem the whole show. But given the lack of intimacy of the hall, just a few coloured gels on the lights could have made it so much better. Even so, it will be a long time before I want to hear a growling trumpet or a tambourine again.