MUSIC / Pickett of the pops: Tess Knighton on five small-scale Brandenburgs at the Purcell Room with the New London Consort

Happily for early music lovers, a new concert series devoted to music up to and including the Bach era has been established at the South Bank. In 1993, the Purcell Room will house a small-scale vocal and instrumental programme planned by the artistic director, Philip Pickett. Pickett aims to bring to London some of the leading specialist performers from the Continent. But it was Pickett's own group, the New London Consort, that inaugurated the series with five of Bach's six Brandenburg Concertos.

There was a time when the Brandenburgs would not have fitted into the Purcell Room, but more recent, one-to-a-part versions have already accustomed our ears to the intimate scale on which, most probably, these works would have been heard in Bach's own day. Indeed, most court orchestras - including the Margrave of Brandenburg's - would have been hard pressed to supply even this minimum. The NLC's performances reinforced the benefits of this approach, though the balance came out almost too much in favour of the 'soloists': perhaps if the ripieno strings had also stood they would have had a more equal say in the musical discourse.

Discourse is undoubtedly an important element in these concertos, and it was, so Pickett's programme note informed us, a rhetorical approach that lay behind the NLC's interpretations. The idea that Bach intended his selection of six, already-composed concertos as a carefully-planned tribute to the Margrave in the manner of 'a textless laudatory ode' is an intriguing one. But the point here was whether such a novel intellectual approach would bear fruit musically. Broader associations of instrumentation - for example, the viols and violas of the sixth concerto suggesting a funeral piece or the trumpety No 2 as a paean to a hero - worked well, but the finer details of affekt (or the rhetoric of emotion) are decidedly trickier to convey to a modern audience. No one would dispute that the NLC captured the expressiveness of the different movements as well as any group. At only two points did their interpretations differ significantly from any other: in the violin solos of the first movement of No 4 and the harpsichord cadenza of No 5, where the phrasing and rhythm were pulled around in a way that was deliberately indulgent. Rhetoric and structure seemed here to be uncomfortable bedfellows.

There is clearly still a long way to go before we can draw near to a lost aesthetic as elusive as that of 18th-century musical rhetoric, but Pickett and his team are to be applauded for attempting to head in that direction - and for their highly polished playing. The acoustic of the Purcell Room seems to favour strings, and in many ways Concertos Nos 3 and 6 were most successful. The viola- playing of Pavlo Beznosiuk and Catherine Mackintosh in the last concerto was quite outstanding, rich in tone and musically alert and inventive: with sonorous support from the viols, this was a musical discourse of real depth.