The close proximity of Simon Rattle’s latest survey of the symphonies with the majestic Berlin Philharmonic Orchestra only serves to highlight the stark difference in approach adopted by Okko Kamu and his leaner lither, Lahti Symphony. Actually, it is the character and sound of that orchestra that makes the difference, with cleaner contours, sharper reflexes and, from the BIS engineers, a greater immediacy of the all-important woodwind voices. Inner parts are thrown into sharp relief. It enables Kamu to highlight the harmonic daring of the music and to move it from stasis to action almost instantaneously.

Of course, one occasionally misses the tonal splendour of such orchestras as the Berlin Philharmonic, be it for Rattle or Karajan, and the famed Berlin string basses anchor this music in ways that the markedly lighter Lahti section cannot. Kamu’s violins, too, are thin by comparison with the world’s finest, and the big tunes of the First and Second symphonies might be found wanting by some. But there are significant benefits to be had from greater mobility, and the rhythmic nature of this music is far better served here than by the somewhat ungainly Berliners. Osmo Vänskä has taught us how vital that is to the imperative of these pieces – and his cycle with the Lahti orchestra remains super-compelling.

But Kamu has a view, a very personal one, and what he always catches is the intrigue of this music. He is self-evidently inquisitive and, familiar though the music undoubtedly is to him, he always gives us a sense of ‘exploration’, of not quite knowing where we might be headed next. The pale clarinet solo at the opening of the First Symphony is like an intrepid explorer, scenting the unknown at the start of the journey. It is quite magically and mysteriously shaded. And when did you last hear the dissonance quite so exposed in the first gusty tutti? Nor is Kamu afraid to create space in moments of stasis; a change in the complexion of the landscape is always marked by an intensifying of the atmosphere therein. Some readers may recall Kamu’s debut recording of the Second Symphony with the Berlin Philharmonic from 1970. The younger man was showing off, grossly exaggerating the gaping silences that punctuate the brassy, elemental upheavals of the second movement. Such excesses have since been ironed out, though he still capitalises on the contrasts both in tempo and dynamics. I love the really hyper-vivacissimo of the scherzo here. By contrast, the arrival, on the crest of gleaming horn fanfares, of the famous tune in the finale is fiercely traditional in its expansiveness.

If I’m honest, I think the Karajans and Rattles better serve – in sonic terms – the Wagnerian orations of the Fourth Symphony’s two slow movements, though Kamu is certainly in tune with the epic spareness of the piece. His string basses may not be sunk too deep to fathom at the opening of the piece, but the sage old voice of the cello solo that follows conveys a melancholy that has nothing to do with beauty of sound and everything to do with wisdom long acquired. There is often an intimacy about the reading, a sense of being drawn in, as when ‘indeterminate’ passages (in the first and third movements) suddenly reflect an unease in nature.

Where rhythm and concision are everything – in the Third and Sixth Symphonies – Kamu and his orchestra are fresh and engaging. In the Third he manages to be tight and rhythmic but also open and airy, and there is a homespun quality about the middle movement, especially in the passage for solo strings. The Sixth is all about pellucidity and the keenness of light reflecting off its cool clean surfaces. The classical abstraction of this piece leaves some cold, but I am intrigued by how it manages to be at once detached and involving.

There are better accounts of the Fifth in the catalogue, including Rattle and Colin Davis, but there is no escaping Kamu’s personal connection with this landscape or the abiding logic of these performances, and the brassiness of the Lahti trumpets makes for a bright new day in the romping coda of the first movement. But again, here and elsewhere in the cycle – the opening of the Seventh – I am conscious of a pervading lightness in the bass-lines; a lack of depth and heft.

So no more of an overall recommendation than with Rattle, and of the home-grown practitioners I still incline towards Vänskä. But Kamu’s readings make sound musical and intellectual sense, and, more importantly, hold fast to the music’s innate mystery. The hopeful C major barely established before being cut short at the close of the Seventh is perhaps the most tantalising unanswered question in 20th-century music. And so it remained.