Following 10 years’ renovation and expansion, St Martin-in-the-Fields is open again for business. Baroque Encounters, celebrating the reopening of James Gibbs’s masterpiece, was launched with a concert by the Amsterdam Baroque Orchestra under Ton Koopman.

The programme was unusual. Four harpsichords had been assembled to allow for a presentation of Bach concertos for two, three and four keyboards, with just five string players representing the ABO.

Although four harpsichords in full flight make a terrific clatter, the orchestral lines were never obscured. Nor were the divisions between ritornello and concertino, the latter being signified by a reduction from five to two or three instruments, as well as in dynamics.

Koopman took centre stage, joined in various permutations by Tini Mathot, Patrizia Marisaldi and Pietro Paganini. In terms of sheer stamina — volleys of virtuosic semi- and demisemiquavers were kept up all evening — Koopman and colleagues left one gasping with incredulity. The sense of swing and momentum was infectious but equally impressive was the crystalline articulation, glittering like the repainted gold decoration high above the Choir.

Koopman has always had a penchant for bravura ornamentation bordering on ostentation. In the slow movement of BWV 1062 it came into its own. BWV 1062 is Bach’s own transcription of his D minor Concerto for Two Violins, and in place of the long meditative lines of the slow movement, Koopman elaborated decoration of audacious invention. I loved it.

Series continues to 16 May (020 7766 1100; www.smitf.org)