Apollo's Fire, St John's Smith Square

Last time I saw Apollo's Fire perform they danced. Halfway through the concert the chamber orchestra just put music stands aside, continued playing their instruments, and broke into a stately minuet on the Wigmore Hall stage.

Nothing quite so unexpected happened at their second London appearance this week at St John's Smith Square, but that same maverick energy was still there, translated this time into some quirky programming and some serious energy from Cleveland's favourite early music group.

It helped that they were joined by French soprano Sandrine Piau. A favourite collaborator of William Christie, Alan Curtis, René Jacobs and really anyone who matters in baroque music, this was a rare opportunity in England to hear her perform some of the French baroque repertoire that is so completely in her blood. Piau's isn't a big voice, and that's a large part of its charm. It is, however, perfectly calibrated - even from top to bottom and capable of uncurling into sensuous delicacy or frothing passion.

Apollo's Fire are a wonderful antidote to too much British baroque

Here we had both. "Règne Amour" from Rameau's Anacreon fizzed with coloratura embellishments - gilded even as the theatres for which this music was written, before Piau melted into the exquisite "Viens Hymen" from Les Indes Galantes. Joined by an obbligato flute (Kathie Stewart), Piau (pictured below) stretched into an endless melody, refining her tone down to its purest and simplest to conjure this bucolic aria fantasy.

There were similar contrasts in Handel, from the poise of "Il primo ardor" (Ariodante), technique barely ruffled by its athletic demands, to the slow-motion drama of "Ah mio cor!" - ten minutes of sustained psychodrama that are hard to pull off in the opera house with the help of context and sets, and which really test in concert. Although I missed the husky colour of a bassoon to double the agitated, pacing cellos, Piau supplemented any lack with her understated simplicity - doing less rather than more and allowing Handel's music to do its work. It's an approach I'd have loved to see repeated in Cleopatra's "Piangerò". If ever there was an aria that called out for a change of mood rather than ornamentation for the da capo it's this one. For all the tasteful beauty of Piau's adornments it was hard not to miss the unfussy clarity of the original lines. Emotional simplicity was lost too, though Piau created an unusually determined Cleopatra, fighting still through the repeat rather than resigning herself to death and failure in the tiniest pianissimos normally conjured here.

And what of the orchestra? Sensitive accompanists, they also had plenty of opportunity to stand alone. Artistic director Jeannette Sorrell (pictured left) knows her repertoire well, and chose a wonderful selection of works to showcase her band. Vivaldi's Concerto for Two Cellos in G minor is a delight - a ferocious battle of "Anything I can do..." proportions between the two soloists. With only 15 musicians, including Sorrell herself directing from the harpsichord, Apollo's Fire were here in decidedly pared-down form, and the two cellists slipped between solo and continuo duties. The results were exciting, but for some intonation issues for the principal cello, which persisted throughout the evening. I've never seen a group tune so lengthily or persistently - for a good five minutes for each 10 minutes of performance. In a venue neither extraordinarily hot or cold this is just too much, seriously distracting (along with too much clapping) from the musical flow.

Sorrell's free way with this music and love of a good rubato won't be to everyone's taste, but within the context of this idiosyncratic group's live performances it works well. Their party piece is Sorrell's own arrangement for string orchestra of Vivaldi's variations on "La Folia". Described by Sorrell as a "baroque jam session", it was great to see music stands put away for this dancing, stamping piece of musical madness. The group are natural communicators, and it was a lovely opportunity to see their workings and interplay without any of the usual straijackets or formalities of presentation.

Apollo's Fire are a wonderful antidote to too much British baroque. For all their technical strengths, sometimes it's hard not to long for just a little more abandon from the Orchestra of the Age of Enlightenment or something a little less laboriously tasteful from the Academy of Ancient Music. The Cleveland Baroque Orchestra have fun with their material, obedient but never slavish to concerns of authenticity. Next time they visit though, I'd love to see them back at the Wigmore. St John's Smith Square is a beautiful venue, but one singularly unsympathetic to small forces, and in the huge space with its vaulted stage even their extraordinary energy was at risk of being swallowed up at times.