A large international audience of keen Sibelians has made its way to this distant provincial town, and been amply rewarded by the performances so far, and this was no exception. There has been a Sibelius Festival in the Finnish town of Lahti since 2000, when its world-class lakeside concert hall opened. For this 150th anniversary of the composer’s birth, the festival has been extended from three days to a week with six orchestral concerts shared between three orchestras, conducted by five leading Finnish Sibelians; Leif Segerstam, Osmo Vänskä, Okko Kamu, Sakari Oramo and Jukka-Pekka Saraste.

This time it was the turn of the BBC Symphony Orchestra, escaping Proms duty to be here for two nights. On their first night they gave an overwhelming account of Kullervo, even finer than their recent Proms outing of this neglected work. This evening they were led by Okko Kamu, whose new set of Sibelius symphonies has been flying off the shelves all week. There were just two central works of the Sibelius canon: the Violin Concerto and the Second Symphony – hence an evening in the key of D, minor and major respectively. The Concerto was given in the revised version of 1905, the one now universally familiar.

The violinist was young Sergey Malov, winner of competitions in 2008 and 2011 and who also plays the viola, the Baroque violin, and the cello da spalla, but here was in his core role of soloist in a virtuoso late Romantic concerto. He is well suited to that role, with a gleaming tone and great dexterity. On this evidence, it is not a big sound, but it was eminently appropriate for the ingratiatingly lyrical opening, that long cantilena whose increasing agitation eventually awakens the orchestra from its somnolent accompaniment to a passionate climax, when Kamu could first give the superbly responsive BBC orchestra its head. Kamu and Malov have worked together before and they were very much as one throughout. The slow movement was sensitively done but also had a just perceptible sense of onward flow, never getting becalmed. The finale, once described by Donald Tovey as a “polonaise for polar bears” which, while zoologically unsound (a ‘burlesque for brown bears’ would be all one could see in the Finnish forests), at least conveys the lumbering liveliness of the music, which was splendidly brought off by Malov and Kamu. Malov got a reception that elicited an encore, which (fortunately) he announced. It was the dazzling Presto finale of Bartok’s Sonata for Solo Violin, a sort of modernist Flight of the Bumblebee, which seemed almost to contain nearly as many notes as the whole concerto, but in just five minutes. It could be the only music in this huge festival week, song and chamber recitals included, not by Sibelius.

The Symphony no. 2 in D major has deservedly been one of the Finnish master’s most played works ever since he conducted its triumphant première in Helsinki in1902. Then it was regarded as a nationalist statement, portraying Finnish resistance to the oppressive yoke of the Tsarist overlords, a view that persisted despite the composer’s disavowals of such connotations. Nowadays the emotional temperature of this music seems a bit lower than that, or at least that is the way it usually played. Once analysts pointed out that this huge and melodically varied work is actually fairly tightly integrated, there was no need to apologise for its passionate eloquence. Kamu certainly kept a tight rein, and did not over do the grand romantic moments. But he nonetheless gave a very satisfying account, with the big melodies having plenty of attack and volume, not least in the tremendous finale, which the BBC players relished, right up until the trumpet-capped coda – no wonder the Finns wanted to storm the barricades after that! Rather than inciting rebellion though, we had to be satisfied simply with an encore – the Valse triste, opening with just the right degree of haunted empty ballroom eeriness, and moving on to a swirling ecstatic climax.

The BBCSO musicians seemed to exploit the wonderful acoustic of this now famous hall increasingly as the concert went on. The woodwinds, so critical in Sibelius, distilled the magical essence of the nature-inspired passages. But it must take time to adjust from the usual thankless task of making a really alluring sound in the Barbican or Royal Albert Hall. There were not many true pianissimi on display at first, but in the Symphony and especially the encore, they dared some whispering tone that was very beautiful.