An afternoon in late January, midway through the Swiss Alpine Sommets Musicaux de Gstaad festival, and in the lounge of Gstaad’s Hotel Bernerhof, Alexandre Kantorow is being a complete trooper. Fresh off the mountain train, with a solo evening recital ahead of him in nearby Rougemont Church, he should ideally be checking into his room and snatching a few precious moments to catch his breath. But since the next 20 minutes are his only free window for an interview, he’s instead gamely parking his suitcase, whipping off his snow-dusted coat and amenably diving fast into talk of the programme he will be playing, and will then record the following week. In fact, if you were wondering why Kantorow, still only 27, is increasingly becoming one of today’s most in-demand pianists – beyond that famous double win at the 2019 Tchaikovsky Competition and his obvious talent – then you’ll find it in this combination of good-natured cooperation, instant focus and sheer naturalness.

The programme we’re discussing constitutes the final instalment of a three-album project Kantorow has had bubbling away since 2020, presenting Brahms’s three piano sonatas, one per album, alongside partner works offering various wider contexts. These sonatas are early works, and Kantorow has saved the very earliest for last, pairing the C major Piano Sonata No 1, Op 1, with Schubert’s Wanderer Fantasy, to demonstrate their rhythmic similarities. Further cross-referencing comes with Schubert lieder transcriptions by Liszt that Kantarow has programmed between the Brahms and Schubert, referencing the songs buried in them both.

Kantorow needs no encouragement to wax lyrical about early Brahms. ‘He really feels like a young composer who explores,’ he enthuses. ‘Of course, he’s taking elements of the past and expanding upon them, such as small Beethovenian motifs; but then he gets as wild as Liszt in the creativity of the structure.’ I comment that Brahms’s First Sonata gets relatively few airings. ‘I think it may be lack of tunes!’ Kantorow smiles. ‘There’s not a lot of relationship to melody. It just kind of goes in a big structural Beethovenian way. You feel how he wants to treat the piano orchestrally. You really feel the horn at certain moments. There’s also a lot of actual experimentation in the piano-writing. It’s not very conventional, and not very nice on the fingers. So the challenge is how to put it together in way that makes people think, “wow! what a journey”.’

There is an equivalent ‘wow factor’ in Kantorow’s choice of recording venue: the Salle de Musique of the Société de Musique, La Chaux-de-Fonds, with its 1966 Steinway on which Claudio Arrau used to record. This is the first album that Kantorow has recorded in these famously ideal conditions, lured by an August 2022 experience in the hall that left him hungry for more. ‘Generally I always change places for each recording, because I’m curious to try new things, and each time we’ve had a new idea,’ he begins. ‘Sometimes it has been a church. There was also a “shoebox” hall in Paris that was really challenging to play in, and I’m lucky to have a sound engineer [Jens Braun] who’s amazing for me. But last time we thought that maybe it’s time to give ourselves a treat, and go in a place where everybody tells us the recording quality is amazing and we don’t need to adapt like crazy to make it work!’ Hence La Chaux-de-Fonds – and while Kantorow took the precaution of having a modern piano brought in for him, once in the hall, he fell in love with Arrau’s piano. ‘It was covered when we arrived,’ he remembers, ‘and when we pulled it onstage and I started playing, I realised there was a lot there. I just wanted to experience it more and more; and the hall itself also brings a lot, because it’s big but at the same time keeps the intimate feeling.’ As for the instrument’s qualities, ‘It’s a type of sound that comes from a different way of making instruments’, he observes. ‘What it lacks in super tension of strings, and ability to project in a 2000-seat hall, it gains in the harmonics and colours. The medium sound is so rich, and very dark. It feels like hot chocolate in a way. You can go really deep in your hands. You can have enormous dimensions of layers, and a note’s timbre changes enormously depending on the attack. You can also do a lot more with pedal – there are a lot of harmonics, and pedal changes aren’t as clear-cut as modern pianos, meaning you can play a lot with notes melting together.’ As his analysis proceeds, it’s striking the extent to which he sounds just as string players do when they’ve had a brief opportunity to switch from their own recently made instrument to an old Cremonese one such as a Stradivarius. ‘This thing where you can feel a personality in the instrument …’, he muses. ‘Something that feels mysterious; that makes you want to delve more into it, and afterwards leaves you with sounds in your mind that you can then try to recapture on other pianos.’

To return to this mysterious, magical combination of piano and room for his final Brahms album, though, has meant embracing some decidedly non-ideal surrounding conditions. For a start, whereas Kantorow usually records as the culmination of a performance project, the Sommets Musicaux de Gstaad concert – his final chance to perform the programme before recording it – will be only the third time he has ever performed it in public. Furthermore, the recording sessions will then happen overnight.

‘Yeah, well it started in a very pragmatic way,’ he laughs as my face suggests that these conditions are not the easiest. ‘I hadn’t had a lot of time to build this programme, and I was set to do a big tour of it in March, by which time I wanted to be very clear on what I wanted in the music. So, when I know that recording is one of the best ways to cement your way of playing, I thought it was really important to try something new and record it before. And then the hall wasn’t available, so the only logical solution I could come up with was to ask whether it was free during the nights, and they said yes!’ Yet on this snowy February afternoon, Kantorow doesn’t look or sound grimly filled with trepidation, but simply curious as to how he’ll find treating a recording as part of the interpretative process. ‘Practising at night is always a special feeling, too,’ he points out. ‘That sense of being the only active person in a sleeping town. I don’t know how that will translate into recording, because in sessions you need inspiration, and a lot of energy and will, to keep going. But in the days leading up to it I shall physically prepare myself by trying not to sleep at night, and instead more in the day.’ In addition, he has built in a small safety net: a return to the Société de Musique to perform the recital in concert – with the opportunity to record that day’s rehearsal, and indeed to hear whether his interpretation has changed very much over the course of the intervening period’s concerts.

Back in Gstaad, though, I ask how the pieces are currently feeling. ‘Extremely exciting,’ he responds. ‘Very unpredictable. For now, there’s a lot that’s left a bit to the mystery of the moment and adrenalin.’ So is it changing quite dramatically from performance to performance, I ask. ‘Yes, absolutely.’ And in each of his two previous performances of this programme, has he been deliberately taking risks, or just going with how it feels in the moment? ‘The latter,’ he answers. ‘For me with a new programme, at the moment of the concert it’s really instinct and adrenalin that are the drivers. Then, block by block, certain parts come really together. You feel what’s not yet developed, what’s not yet convincing or doesn’t hold the audience, and then you slowly adapt, and after a few concerts it’s very different – you’re instead deciding what you’re going to do in the moment in a very clear, conscious way.’ And with that, we need to conclude our interview. With the evening’s concert in his mind’s eye, Kantorow apologises as he scoots himself and his suitcase away.

Fast forward to a snow-blanketed Rougemont Church that evening, and Kantorow is a human whirlwind – an entrance onstage so swift that it’s as if he’s popped out of nowhere, then exploding into the Brahms at the second his body makes contact with the piano stool – and onwards into a reading of electrifying passion and power, his intakes of breath audible from midway back in the stalls, the piano becoming an orchestra as his successive layers of colours reverberate – and low-register rolls thunder thrillingly – around the ancient church space. The applause almost lifts the roof. Then next, a Wanderer clearly accentuating the motivic connections between the two works, followed by lyrically voiced Schubert-Liszt song transcriptions.

Kantorow is no less squeezed for time when, some weeks later, we complete the interview. This time he’s on his mobile, sitting on a plane as its final preflight checks and safety demonstrations are carried out, and once again I am amazed by his focus and good-humoured willingness to fit me into a clearly insane schedule. I ask how the concert felt, and he laughs. ‘That night felt very intense. It was cold at the back of the church, and there was no piano. So beforehand I was just trying to keep as warm as possible, wrapped up in scarves, and I think I was really pumped up with adrenalin as I went into the Brahms. I felt there was a lot of energy in this interpretation. Even not always pulling back on tempo and rhythm. People could perhaps sense this stress and excitement emanating from me, and what I loved about that performance was that I saw how far, emotionally, I could go.’

‘Intense’ is also how he describes the following week’s sessions. ‘It was in a way the most concentrated recording I have ever done, because it was really in one take each time, for five hours non-stop,’ he remembers. ‘I think it really allowed a lot of deepening in certain aspects. And when the tiredness was really hitting, having already played it a number of times, I was able to draw on my memory of the emotional place I’d been in the night of the concert, and remember how exciting it could be.’

And did the piano live up to his expectations? ‘Honestly, it’s a magical piano,’ he confirms. ‘When you put the pedal on and you get this wash, this wave of sound, rising out … It was a perfect instrument for the Schubert lieder, because you could take it as far as you wanted in the colours. You could go as low as possible with the dynamics, and it would still sing. Then afterwards, you’ve got this sound beacon in your memory, which you can then find a way to reconnect with on a modern grand piano.’

As we speak, the Chaux-de-Fonds concert with its second patching session is yet to come. The plan, he tells me, is to take maybe three hours of recording, ‘just to see what changed. So in the end, I believe it will still have been a cumulative experience.’ And certainly at this point things are still moving. ‘Even if I have a bit more experience today, I’m still nowhere near to having made all decisions, and that’s the joy. I’m doing the most enormous amount of concerts of this programme, and each acoustic, each different piano, gives something new, a different light.’ As for whether this is a process he’d be up for repeating, ‘Maybe’ he muses. ‘I don’t know. It’s a bit of a luxury to be able to do a recording before and after, but I will see how it turns out in the end with the editing – whether it’s something interesting.’ And now, after all this time, with the sounds and emotions of that Sommets Musicaux de Gstaad concert still reverberating around my head, the resulting album stands triumphantly – for me, and one hopes for Kantorow himself – as a potently evocative souvenir of an especially intense period of thought and experimentation from an artist who never stands still.