PROMS 1997 Bach Evening Royal Albert Hall, London / BBC Radio 3

Visitors to Monday night's Bach Prom by the Amsterdam Baroque Orchestra and Chamber Choir under Ton Koopman might have been forgiven for mistaking Cantata No 214's "Sound, ye drums! Ring out, trumpets!" for the opening chorus of Bach's Christmas Oratorio. In fact, the two are virtually identical. The cantata was composed to celebrate the birthday of Maria Josepha, Queen of Poland, and received its first performance, in all probability, at Zimmermann's coffee house - a less spacious acoustic, one supposes, than the Royal Albert Hall. Chorus and timpani rang resplendent, but baroque flutes and oboes quite failed to project and certain string lines flatly refused to leave the stage. There's little doubt that, when it comes to Bach for orchestra, the RAH is best served by modern instruments or, better still, by the lavish orchestrations of Sir Henry Wood, Stokowski or Respighi. Monday's performance, however, had all the expected Koopman characteristics: crisp, buoyant rhythms, keenly attenuated phrasing and - as far as one could tell - sensitive balancing between instrumental choirs. Soprano Suzie LeBlanc exhibited admirable agility but occasionally sounded off-colour, whereas alto Elisabeth von Magnus was prone to stumble over her "Gentle muses". Tenor Mark Padmore and bass Klaus Mertens were uniformly excellent, and the chorus superb.

Koopman's well-planned programme continued with a fine performance of the Fourth Brandenburg Concerto, although the flexible solo violin line (Margaret Faultless) hit a few rough patches and the tastefully embellished harpsichord continuo was virtually inaudible. It was rather like viewing a rich-hued painting through the wrong end of a telescope, sensing detail without actually being able to see any of it properly.

After the interval, the Amsterdam Baroque Choir was joined by a cello, a double-bass and a lute for an exquisite performance of the Motet Jesu, meine Freude, six verses of a hymn by Johann Franck interspersed with passages from St Paul's Epistle to the Romans. Koopman's feeling for imaginative wordplay illuminated the interludes between chorales (those based on chapters from Romans) where Bach's writing approximates the elevated choruses in the St Matthew Passion. Cantata No 21, Ich hatte viel Bekummernis (In the multitude of my thoughts), inspired ecstatic involvement that paid even higher dividends - in the dialogue between Jesus and the Soul, for example, where the Soul begs for deliverance and Jesus pledges his love. Suzie LeBlanc was by now fully back on form and Klaus Mertens responded to her with the utmost sensitivity. The cantata is cast in two sections and rates among Bach's greatest. The narrative is extraordinarily moving, and the scoring - for three trumpets, cornett, trombones, drums, oboe, bassoon, and strings and continuo - unusually colourful. The closing chorus "Worthy is the Lamb" raised the expected storm - stamping, cheering and wild applause. Koopman and his singers returned again and again, eventually relenting with a vigorous repeat performance. We left edified, humbled and freshly convinced that, in the final reckoning, it has to be said that JSB was the greatest of them all.