Britten Sinfonia / Joanna MacGregor / Andy Sheppard, CBSO Centre, Birmingham

Jazz rules were in force at this concert (or gig?), meaning that drinks could be taken into the venue. The last Britten Sinfonia tour featured the music of John Zorn and Frank Zappa, and their commitment to genre cross-fertilisation remains strong under the artistic direction of Joanna MacGregor. This is her second tour with the 15-piece Sinfonia, which is now in its 11th year.

The rebel pianist has assembled a programme that begins with Dumbarton Oaks, one of Stravinsky's more conventional works. Then it leaps radically into a selection of short pieces by the New York busker Moondog. The Art of Fugue provides the tour with its title, MacGregor having arranged JS Bach's final work to include the improvisatory presence of the jazz saxophonist Andy Sheppard and the Indian classical multi-instrumentalist Shrikanth Sriram. Alternatively, when playing tabla, fretless bass guitar or flute with Nitin Sawhney or the DJ Badmarsh, he's known simply as Shri.

MacGregor saw Moondog perform in 1995 and was captivated by his conglomeration of jazz, beat poetry, classical and Native American motifs. Not much of this one-man band's music is in published form, so her arranging was often geared toward transcription and imitation of his live street recordings, or studio experiments with invented percussion objects and overdubbed vocal layers.

MacGregor has arranged 12 of her favourites, stretching from the 1950s to Moondog's 1990s pieces. The original "All Is Loneliness" appears on tape, and there are regular intrusions of Manhattan traffic-noise. She plucks strings inside the piano and uses her synthesiser for its harpsichord setting. MacGregor is quite wooden when keen to look funky, over-compensating with a conducting jerkiness; that quality was echoed in the stiffness of the Sinfonia. It must be said that there is a clip-clop crankiness to the originals. Unfortunately, the transitions between the short pieces are ungainly, and the players seemed tense in their pursuit of beatnik syncopation.

Sheppard's solo parts need more amplification, but Shri's overblown bansuri flute has no such problem on "Invocation". The audience is confused over when to clap, but before the Moondog numbers reach the half-way point, the applause follows every tune, usually prompted by one of Sheppard's soloing climaxes.

The Art of Fugue is rarely performed, because of its abstract nature, and MacGregor admits to being intimidated by her own intentions. She has made a concise version by selecting and sacrificing. The instrumentation was never specified by Bach, so there's a temptation to openness.

The problems that can often dog jazz-classical fusions (indeed, any kind of fusion) are solved here, or even avoided. The alternating emphasis between moderately faithful interpretation and improvised waywardness happens in a seamless, naturalistic fashion. MacGregor has encouraged Sheppard to be himself, force-feeding him notation but allowing the gentle roughness of his feline-tongued tone. Cannily, she has simultaneously coerced Sinfonia members into frequent freeform gestures.

Despite any hyperactivity, most of MacGregor's arrangement casts a soothing, contemplative spell over the audience - not the usual by-product of experimentation. But Bach's rebirth is more successful than Moondog's.

The Art of Fugue tour continues at RNCM, Manchester (Thursday) and Colston Hall, Bristol (9 December)