Now this is how you put together a program of contrasts! Members of the Chamber Orchestra of Europe, on this night anchored by the presence of Pierre-Laurent Aimard, led us through a series of wild, compact, adventurous, and sometimes severe works by Bartók, Janáček, and Ligeti, before turning after the intermission to – what else? – Mozart’s G major Piano Concerto, K453. This was no grab-bag assortment of classical music goodies, but rather a small collection of pieces that emerge in sharper relief in one another’s midst.

The Bartók Kontraste, for a trio consisting of piano, violin and clarinet, features three scenes of collaboration for an ensemble that consisted at its première of Joseph Szigeti, Benny Goodman, and the composer himself. The piece is, suitably, at turns jazz-idiomatic, folkloric, and intellectual, with some wonderfully polyphonic solo moments for the clarinet and passages of high-speed linear coordination in the last movement. On this occasion, the trio consisted of Aimard with violinist Lorenza Borrani and clarinettist Romain Guyot, all of them extraordinarily precise and infectiously energetic.

Then followed the Janáček Concertino for piano and chamber orchestra, which was a most delightful discovery for me. It is both sparing and rich, for instance in the first movement, which is a duet for only horn and piano. It’s an unlikely marriage, but miraculously Aimard and the phenomenal hornist Stephen Stirling managed to find a common sound between their instruments, leading one to believe, in hearing them, that no instrument pairing could be more inevitable.

The Concertino doesn’t mobilize the whole ensemble at once but picks out duets and trios here and there, so that the orchestra is treated less as a single body than as a set of resources. The second movement, like the first, starts with the piano paired with a single other instrument, this time the clarinet, demonstrating its fleetness with a series of rapid trills that the pianist rebukes with stolid chords. Additional instruments make an appearance only in the last measures of the movement, recalling – or rather, foreshadowing – Ligeti’s Musica Ricercata, in which the movements are restricted to, first, a dyad, then a triad, then a quartet, a further element making an appearance only at the end of each exploration.

Ligeti’s Kammerkonzert is, however, far from a concentrated exploration of limited means, but instead like the swarming sound of the atmosphere, another of Ligeti’s recurring idioms. This music is impersonal, forceful, and arresting. One of the piece’s driving strategies is the finding of unstable textures that eventually reach precise points of articulation, so that the piece constantly vacillates between unrest and an uneasy placidity. It is a ferociously difficult work, and Aimard led the ensemble in an utterly convincing reading.

And then, finally, Mozart, whom I love as much as anybody, and yet I think his necessity has never better been argued for than by his placement after Ligeti’s uncompromising Kammerkonzert. One hears only correspondences in the juxtaposition: the composers’ mutual mastery of long continuities of line, the way they manage internal disturbances, the way they get ensembles to talk together. As for the way it was played: we all, I think, need more of Aimard playing Mozart in our lives. Both conducting and playing, he mostly let the orchestra do its thing while he sat with his back to the audience, a silent anchor. What is so special about his Mozart? For one, the sound, which is closest to a toy piano, not necessarily in its timbre but rather in the fluidity and physicality of the phrasing. Hearing Aimard play, you realize how much most pianists have unwittingly absorbed Beethoven and Brahms in the way they conduct a Mozartean rubato, or reach for a high note. With Aimard, the phrasing is rounder and, I want to say, more honest. No-one knows how Mozart sounded when he played his own works, but it may well have sounded like this.

Of all the wonders of his playing, it was his second movement that took the cake. I will only say that there is a hesitation in the very first phrase the pianist plays that everyone who was there on this night will remember; also, a single time, during the cadenza, that Aimard blurred two notes together, the perfect time, the only possible time. What would it mean to call his Mozart revelatory? What has he revealed? Perhaps nothing more than that he should be considered, if he is not already, among the best pianists and musicians of our time.