Hesperion XXI / Jordi Savall, St John's, Smith Square, London

Now in his sixties, the Catalan viola da gamba virtuoso Jordi Savall surely remains among the most magnetic figures in early music. Despite the manifold demands of scholarship and conducting, of running a variety of specialist ensembles and recording, by now, a vast discography ranging from the remotest past up to the early-19th century, his playing somehow retains an inimitable spontaneity and finesse – as heard once more in his two concerts in this year's Lufthansa Festival of Baroque Music.

Or rather, as overheard – for the resonant spaces of St John's, Smith Square, tended too easily to blur and distance the sound in the first concert, in which he was joined only by the engaging Spanish guitarist and lutenist Xavier Diaz and the impress-ive German harpsichordist Michael Behringer. Curiously, it was the solo items in this programme of vernacular-dance-based baroque repertoire that projected best – whether the deliciously silvery tone of Diaz's guitar in exotic dances by Gaspar Sanz, or the panoply of fantastical gestures and string effects in Savall's own selection from the Musicall Humors of the eccentric Englishman, Captain Tobias Hume.

It was when the gamba was enmeshed in elaborate continuo figuration of lute and harpsichord that clarity tended to get lost, though this could not prevent the Couplets de Folies – Marin Marais's majestic set of 32 variations on the ubiquitous folia dance-pattern – from accumulating due gravity. And in the second concert, the penetrating tone of the five viols and lute of Hesperion XXI, with Savall now leading from treble viol, came over more immediately in an intricate programme of English consort music from Byrd to Purcell, interspersed with florid Italian monody from the early baroque.

Unfortunately, Hesperion XXI's long-term star singer, that quintessentially Iberian soprano Montserrat Figueras, was in far from best voice. Whether or not from some undivulged throat infection, pitch and tone were only sustained with difficulty and consonants often swallowed in her three elaborate arias by Giulio Caccini (co-inventor of opera) – though her Spanish folksong encores were spirited enough. And her disability also meant some unsettling programme changes on the hoof.

Still, the players recovered their habitual poise and intensity soon enough, offering lucid and vibrant accounts of In Nomine settings by Byrd and Gibbons, and of Purcell's celebrated Fantasia upon one note, and irresistibly lilting readings of a pair of Galliards by Anthony Holborne. And if, for some reason, Savall chose to omit the repeat of the final section of Dowland's disturbed Pavan: Semper Dowland semper dolens, Hesperion XXI's realisation of William Lawes's Pavan in C, in all its sumptuous serenity, proved the high spot of the evening.