Looking through the programmes of the Barbican's four summer weekends of Mostly Mozart, it is possible to imagine that the period-instrument revolution never happened. There's not a gut string or a natural horn within earshot. These performances of Mozart and his contemporaries are all being given as they would have been at any time in the long history of the Academy of St Martin in the Fields. That traditionalism doesn't devalue the results, of course. But in the context of a concert series that seems designed to be both approachable and informative, it seems odd that no place could be found for one of the British period bands so that the audience was given some sense of what such an approach can bring to this repertoire.

On its own terms, though, this was a stylish and rewarding concert. With Jiri Belohlavek conducting, intense, pointed performances were ensured. His economical platform style brought the immediate rewards of top-notch ensemble playing and carefully rendered detail in the overture to Mozart's La Clemenza di Tito. His contributions to Mozart's D minor Piano Concerto K466 quite outgunned the soloist Nikolai Lugansky for passionate commitment: where Lugansky was content to skate decoratively over the surface of the music, Belohlavek probed much deeper, and gave the opening tutti of the finale, in particular, a power and sense of drama that was almost shockingly vivid.

Conductor and chamber orchestra provided a perfect responsive platform for the mezzo Magdalena Kozena too, in arias from La Clemenza di Tito and Gluck's Paride ed Elena, in which her wonderfully pliant tone and perfectly judged verbal stresses were a constant source of wonder. One of the innovations in these concerts is a pair of giant video screens flanking the platform, providing close-ups of the performers. This proved a mixed blessing, for like many singers Kozena makes some strange faces, narrowing her eyes and twitching her nose when expressing vehemence, and looking for all the world like a fractious ferret. But in Haydn's cantata Arianna a Naxos (prefacing Belohlavek's account of the same composer's Symphony No 96) her dramatic involvement and the sheer beauty of her singing were enough to set all those musteline comparisons to one side.