CLASSICAL MUSIC: Steinitz Bach Players; St John's Smith Square, London

Half a century ago, a chorus of 80 singers was thought of as verging on the dangerously small side to do full justice to the vocal works of JS Bach. In January 1947 Paul Steinitz, a free-thinking organist and conductor, set out to liberate the composer's music from the oppressive weight of numbers usually employed by English choral societies. His 60-strong South London Bach Society developed its minimalist tendencies over the years, soon evolving to become the London Bach Society, gradually introducing ancient instruments into its modern orchestral ranks and, most famously, presenting the complete cycle of Bach's surviving cantatas in concerts from 1958 until a few months before Steinitz's death in 1987.

Academic arguments about the size of Bach's Leipzig choirs, like those concerning the number of angels able to dance on a pinhead, can all too easily reduce to the absurd. Steinitz adopted a common-sense approach to the practical application of scholarship, not least in the attractiveness of his programming, a trend since continued by his widow, Margaret, in the annual London Bach Festival. Period instruments and historically informed performances are now the norm, with members of the Steinitz Bach Players familiar by their work for today's high-profile early-music bands. Their contributions to the London Bach Society's 50th-anniversary celebrations at St John's, Smith Square, were distinguished by a captivating variety and subtlety of expression of the sort formerly abandoned in pursuit of the "authentic" voice of Baroque music.

The bold writing and rich instrumentation of Telemann's Suite in B flat again confirmed the Hamburg composer's just claims to a share of the present admiration reserved for his contemporaries Bach and Handel. Here oboist Anthony Robson, given his first break as a period-instrument orchestral player by Paul Steinitz, and bassoonist Philip Turbett negotiated the concerto-like demands of Telemann's score with graceful ease, matched in refinement by Simon Standage and his fiddle colleagues. The lyrical, carefully shaped phrasing and delicate contrasts of wind and string timbres were flattered by the reverberant St John's acoustics, although the same served to rob the edge of clarity from the opening account of Bach's Concerto for harpsichord and strings in F minor, a case of chamber music removed from the chamber, or at least the coffee house, to its detriment. Soloist Paul Nicholson's stylish, flowing delivery of the Largo and athletic finger- work in the finale stood at odds with his rather lumpen, ungainly playing in the first movement.

Bach's Peasant Cantata may not be the wittiest of light-hearted musical diversions, but it was brought to life here by singers Catherine Bott and Paul Robinson, the former milking the irony of the maid's "city" aria and articulating the voice of experience throughout, the latter offering an attractive, light, lyric baritone, well focused and produced within the comfortable bounds of its natural dynamic range. The London Bach Festival deserves credit for prudent use of its resources, harnessing experienced performers alongside first-rate young musicians and thereby preserving a worthwhile tradition of Steinitz family values.

Andrew Stewart