Now this is something very special, and it marks an exciting debut for Leif Ove Andsnes on Sony after his long relationship with EMI. The label has struck musical gold with this particular signing and the pairing of Andsnes with the Mahler Chamber Orchestra makes this a thrilling start to what is termed ‘The Beethoven Journey’. (While that might sound like another Beethoven piano concerto cycle to you or me, it is, to Andsnes, ‘a multi-season project that will make the composer’s music the centerpiece of my life as a performer and recording artist’.) And this is the first time we get to hear Andsnes in Beethoven on disc. He has waited a long time but, on the basis of this CD, was right to do so. He offers a personal but never idiosyncratic view of the First and Third Concertos and it augurs very well for the remainder of the series.

Except that it isn’t just another Beethoven cycle-in-the-making, and the achievement is as much down to the Mahler CO’s youthful players as to Andsnes’s peerless pianism. He directs from the keyboard and this makes for exactly the kind of chamber-musical, hyper-reactive performances that you might expect. But there’s so much more to this partnership than just exceptional playing (though there’s that in abundance): there’s a palpable sense of discovery, of living the music; he and the MCO players are already finishing one another’s musical sentences like an old married couple, but with an ebullience and mutual fascination that is anything but world-weary.

You know you’re in remarkable musical company before the piano has sounded a note. Just listen to the long exposition of the First Concerto: highly responsive, lean strings, pungent horns and wonderfully characterful wind soloists (especially the first bassoon, both alone and in duet with the first oboe). Of course, this isn’t just down to the players: it’s Andsnes’s conception right from the start. Even if we can’t actually see him directing, we can sense his musical presence.

The chamber dimensions of the ensemble mean that these are essentially less ‘public’ readings than those of, for example, Lewis and the BBC SO or Brendel and the VPO (to mention just two other front-runners). But that’s not to suggest that the playing in any way lacks impact. The smaller forces mean that the wind and brass are naturally more prominent in the mix and I found myself hearing details – a flute phrase here, a bassoon response there – that I’d never consciously registered previously. However, these are never pushed at you in a Harnoncourt-y manner (as he can do in his cycle with Aimard). And there are little touches here and there – reducing the violin line to a single player just over two minutes into the opening movement of the Third Concerto – that demonstrate the detail of the thinking behind these interpretations.

What’s also very striking is that these performances are not simply about élan and energy: they have a sense of gravitas, too, of rightness, that you find in the greatest Beethoven interpreters, from Edwin Fischer and Emil Gilels to Alfred Brendel. This isn’t something that is achieved by big, ballsy playing but rather by a sense of balance, of musicality, of understanding not only the notes themselves but the wider context – where these pieces stand within Beethoven’s output and a broader historical perspective, too.

The sign of a really fine orchestra is its adaptability, and it’s fascinating to compare the playing of the MCO here with their disc with Argerich, who recorded the Third Concerto with Abbado in 2004. In the Largo Andsnes and the orchestra hold you rapt at a slow but never stilted tempo; the players have to contend with a still more spacious approach from Argerich, which they do superbly, while in the finale they’re immediately responsive to her swerves of tempo and phrasing (and the first oboe is heroic in both performances). There’s no disputing the greatness of Argerich as a pianist but it’s Andsnes’s more selfless approach that I find more compelling. He writes in the booklet-notes about finding Beethoven simultaneously the most human and the most deeply spiritual of composers, and this is conveyed vividly in these performances.

The pleasure is completed by the wonderfully warm and natural ambience of Prague’s Rudolfinum, beautifully caught by Sony’s engineers. I, for one, can’t wait for the next instalment.