Having only heard Pierre-Laurent Aimard on disc for the last few years it was curious to experience something rather different in the flesh, by way perhaps of that phenomenon, so often invoked as to be meaningless, of the artist for whom two concerts are never the same. I can say with some certainty that it will be some time before we ever hear a piano sound quite the same in the Mozart Saal, a room that habitually bestows brightness and brilliance in unforgiving quantities regardless of model or manufacturer, but which on this occasion was filled with a plush and intimate roundness.

Both books of Debussy preludes, quite a feat in a single sitting, were unified by the evenness of Aimard’s style – nimbleness, articulacy of expression, ample space to breathe – and by the same token never subordinated to it. Much of what Aimard offers can be taken for granted, aided and abetted by the unfussy manner in which it is presented, and yet these and all his other virtues seldom add up to such individuality. Any expectation that this might be put to the service of Debussy by way of Ligeti and Messiaen was repeatedly overturned; destabilization of tonal structures was rendered fluidly with emphasis firmly on expansion of the tonal system. Whatever this may owe to Liszt the resemblance I found coming to mind most closely was second-period Scriabin, the fourth and fifth piano sonatas in particular.

The first three preludes of the first book were anything but weightless and indeed underpinned by B flat to an extent that almost spelled out what might be found in an A-level music textbook, and yet there was room here to allow B natural – introduced alongside the putative tonality in the second chord of “Danseuses de Delphes” – its full functional and sonorous weight. The hesitancy of pushing forward or departing was present here in largely conventional Debussian fashion, and again in the opening bars of “Danseuses de Delphes” and “Voiles”, with the first of the bass B flats placed as no anchor. “Les sons et les parfums tournent dans l'air du soir” began with crystalline transparency put to arresting effect, harmonies sounding much stranger than their appearance on the page. Movement approached with a sense of childlike wonder in “Les collines d'Anacapri”, giving way to a bass line quite a bit more than en dehors but not without balance, while “Des pas sur la neige” was typically plaintive throughout (I continue to wonder what this might sound like closer to the third act of Tristan und Isolde than “Im Treibhaus”; probably an appalling travesty, but the remarkable similarity of contour – purely a coincidence? – is nonetheless there). “La fille aux cheveux de lin” was played straight, perhaps just as well, while there was possibly indeed a touch of Ligeti to the opening of “La sérénade interrompue”, however fleeting that may have been, and again, “La cathédrale engloutie” was played straight in an arch-like expanse, with the astute sense of letting form do its work. Once more something childlike, kept at arm’s length from full-blown whimsy, took over the final two numbers in the set.

“Brouillards” swarmed surely enough with expected lightness of touch and unexpectedly immaculate evenness of distribution accorded to each and every note; unaccented phrasing and judicious pedalling undoubtedly helped but to hear this miniature so fully realized is a rare thing. That the B naturals were not struck as softly as usual in “La puerta del Vino” seemed more or less intentional given what we had heard at the beginning of the evening; for me this didn’t add anything but nor did it impose. The incipit of “Bruyères” one hears to the point of distraction as a jingle on the Viennese classical music station Radio Stephansdom and it was restorative to be exposed to it in its original context, even if as with all of the more familiar preludes of the evening, Aimard pressed through it a little, allowing less time to breathe. In that spirit, “Général Lavine” was a largely no-nonsense affair, albeit with some rather louche ragtime in the middle, which returned to haunt “Hommage à S. Pickwick Esq.” amid the pomposity (and fun poked at it). “Canope” offered the kind of legato and line that its opening chords need, and the triplet asides were as fully integrated. A quizzical start to “Les tierces alternées” eased fluidly into more of what had so compellingly characterized “Brouillards”, and the thought to accompany it that few pianists can pull off such efficiency with such expressiveness, and so unapologetically (perhaps Hamelin now, though others who make no attempt to disguise or conceal this balance cannot be many in number). If that steadiness ever wavered, it did so in “Feux d’artifice”, honesty of craft yielding to grand drama. Some acknowledgement, however fancifully imagined, that for “self-effacing”, “cerebral”, “detached” Debussy playing, this had been quite a journey.