Renaud Capuçon is on a mission to promote Mozart’s Sonatas for Piano and Violin. His recording of the composer’s 16 mature works, made in company with pianist Kit Armstrong, projects the exquisite beauty and jaw-dropping inventive brilliance of scores that are all too often overlooked by violinists in favour of pieces that give star billing to the fiddle. Capuçon and Armstrong first played the cycle at the 2016 Salzburg Festival and formed a regular duo marked by exceptional mutual understanding. Their Mozart playing revolves around an infinitely subtle dialogue. Capuçon’s violin cultivates wonderful tonal contrasts and dramatic emphases, while Armstrong’s eloquent pianism draws out the rich character of each sonata movement. “It’s incredible music,” notes Capuçon. “Every single sonata is a masterpiece.” And yet, he adds, he only knew a handful of them before performing the full set in Mozart’s home city. “The first time I met Kit was with these sonatas. And from our first reading of them, it was incredible. He opened a window on to this world, which I somehow didn’t know. This made me play completely naturally. When Kit plays Mozart, he tells a story and it’s never the same. To be honest, listening to him sometimes, I even forget to play because it’s so beautiful. That’s why from our first note together in Salzburg, I knew we’d record these pieces one day.” The freedom and fluidity of Armstrong’s playing encouraged Capuçon to follow suit. When it came to recording Mozart’s sonatas, the violinist was determined that spontaneity should not be sacrificed on the high altar of perfection. He told Deutsche Grammophon’s producer that they would play each movement twice unless both takes contained fatal flaws. “We finished in four days! It would normally take 12, maybe longer. But we wanted to keep this freedom and, wherever possible, only record each movement two times.” Picking highlights from nearly five hours of music, performed with total conviction and tremendous insight, is no easy matter. But anyone looking for an entry-point should head straight to the Sonata in B-Flat Major, K. 454, a virtuoso workout for both instruments, before striding deeper into the set with the delightful Sonata in D Major, K. 306. “My biggest discovery, well I mean the shock of my life, was the Sonata in E-Flat Major, K. 481, which I hardly knew,” confides Capuçon. “The first time I read it with Kit, I almost cried because of the slow movement—it’s a real journey, quite incredible. I thought, ‘How come I’ve never heard this piece before?’ When I speak about it now with some violinist friends, they say the same.” Mozart, notes Capuçon, suffers from being saddled with the conventional wisdom that his music is harder to play than it looks. “Even before you begin to play one of his concertos in your teens, you’re already paralysed by this thought,” he explains. That’s why he advises his students to enjoy the music and not overthink its interpretation. “At the end of the day, it just has to be free.”