Prom 37: BBC SO / Vänskä/Kavakos, Royal Albert Hall, London

Some concert programmes look strange on paper: works by two Poles and a Finn, conducted by a Finn with a Greek soloist and a British orchestra. Osma Vänskä was conducting the BBCSO for the first time at the Proms and this was a concert that got better and better.

Lutoslawski's Mi-parti began proceedings. Dating from 1976, the work was to an extent inspired by John Cage. For a composer as concerned with the minutiae of detail as Lutoslawski, letting go the reins in terms of Cage-style improvisation where more-or-less anything goes, seemed pretty unlikely. And unlikely it was: the players are allowed to play in tempi of their choice but the fragments are determined by Lutoslawski. Thus the overall sound is not so much free but a re-iteration of distinctly Lutoslawskian-type material. And indeed the composer comments: "[I have] no wish to surrender even the smallest part of my claim to authorship of even the smallest passage of the music which I have written."

So, Communist-controlled ideology attempting to embrace American-style freedom? Well, a British orchestra came up with a wholly convincing performance of this cool, French-coloured work.

Szymanowski's Violin Concerto No 2 was his last major work. This is a work inspired not by American chance methods but by the folk fiddling of the Tatra mountains. Its opening, with piano and keening clarinet does, however, suggest Gershwin.... In fact, the piece is full of exotic touches - side-drum and triangle - that tease the ear into misplacing the work's origin. The Greek soloist, Leonidas Kavakos, might not seem an obvious choice - this is Thomas Zehetmair territory - but the Szymanowski has something of the Finnish about it and Kavakos has recorded the original version of the Sibelius concerto with guess whom? Osma Vänskä. So a certain logic was evident. Kavakos is supremely gifted but remains worryingly disengaged. Where was the passion in the lyrical post-romantic Andantino? His playing of the cadenza revealed Szymanowski's delight in folk fiddling, although a full-throated Stradivarius was hardly the stuff of a Zakopane Mountain fiddle. Kavakos did warm up as the work went on and, "doing a Rossini" in the final bars, sent the audience wild.

But the prize of the evening was a beautiful Sibelius Symphony No 2. From the opening - strings surging, wind perky, brass brassy - this was an edgy, febrile performance. Vänskä kept things moving, carefully shaping the oddly constructed phrases but never losing sight of the bigger picture. Perhaps it does take a Finn to understand the deepest recesses of a Finn. If this was part of a beauty contest to land a new chief conductor for this orchestra, it was a resounding success.

Booking: 020-7589 8212; www.bbc.co.uk/proms. Prom 37 available online until Thursday