Death & Resurrection, St Paul's Cathedral & Tate Modern, London, **

Tate Modern and St Paul's are at opposite ends of more than just the Millennium Bridge, and a joint venture might seem incongruous. But, since January, Tate and Egg, the online bank, have been presenting a series of unorthodox live art events. The first set fire to Tate Modern. Things were calmer at "Lament Tate", Arvo Pärt's largely slow (and thin), 50-minute response to Anish Kapoor's disturbing Turbine Hall sculpture Marsyas, although Peter Sellars's accompanying update of Antonin Artaud's For an End to the Judgement of God (staged as a Pentagon press briefing with "slo-mo" clips of Afghani horrors) still disturbed the peace. There was a common theme: art being worked at very hard.

Most recently, Tate and Egg Live turned to Easter, though, alas, without offering any chocolate accompaniment. Instead, "Death and Resurrection" was the name for a two-part event promoted, perhaps incorrectly, as a collaboration. They presented a "twofer": a concert of the old (Bach) at St Paul's and then of the new (Steve Martland) at the Bankside gallery, with the interlude of a trek across the Millennium Bridge during which the audience waved illuminated wands.

The massive space of St Paul's hosted some of Bach's most sublimely reflective music – Cantata "Der Gerechte Kommt um"; Cantata four, "Christ Lag in Todesbanden"; and Cantata 118, "O Jesu Christ, meins Lebens Licht" – given by the crack Monteverdi Choir and the English Baroque Soloists under the magisterial direction of Sir John Eliot Gardiner.

Hearing Bach in the expectation of moving on the same evening to listen to new work accentuates one's awareness of J S's astonishing writing. The expressive harmonies in the opening of Cantata four and the instrumental colours in Cantata 118 of two litui (ancient valveless trumpets, superbly played by Robert Vanryne and David Hendry), three baroque oboes, and a baroque bassoon left one swooning. In privileged seats under the dome, one could only marvel at the crispness of the strings' bounced notes and the impeccable enunciation of the choir.

Gardiner then brought his choristers to the Turbine Hall to perch high above the crowd – a sight in itself – to sing new versions by Steve Martland of street songs. It was perhaps unfortunate that the lighting for the singers obscured the screen below on which tantalising and disturbing animated images by the estimable Brothers Quay flickered to Martland's music. But the shadows on the wall were nevertheless extraordinary.

Martland's "Oranges and Lemons", "Green Gravel", "Poor Roger", and "Jenny Jones" felt soft and English in relation to the Quays's East European folk imagery, which did manage to shine through. Lasting about 30 minutes and predominantly in smudged grey, white and green, the films developed a loose narrative in four parts: magically-lit eggs surrounded a wizened corpse; a wooden doll emerged from a casket ringing a toy bell; a tree of life shed blood-red fruit as a terrifying old apple-picker spiked the doll; a coffin with an anatomical doll was revealed to be carrying the foetus of a little man and the child/doll was resurrected.

There was no deliberate match to the music; both felt free-standing, a non-collaborative collaboration. Like death and resurrection, perhaps?