“I’ve not got it. Maybe next time,” pianist Pierre-Laurent Aimard muttered into his ever-present microphone at Monday evening’s Mostly Mozart recital, while simultaneously sweeping the score of Boulez’s 1945 Notation 6: Rapide off the piano, after playing only a few bars. The pianist’s usually serene presence at the piano was missing throughout the recital, replaced by an overly-talkative and under-prepared persona, a flurry of expository statements and stammering fingers. Never mind the fact that it’s simply unheard-of to discard a programmed piece in the middle of a performance, a soloist probably should not spend more time talking about music than playing music. Mr Aimard, who is usually so impressive in solo performance, had clearly spent more time devising the program than practicing it.

The concert, which was part of Mostly Mozart’s “A Little Night Music” series of late-night events, was comprised of six preludes, six canons, and George Benjamin’s 2001 composition Shadowlines, six canonic preludes for the piano, which was written for Aimard. This order of events was more compelling in theory than in practice. Mr Aimard did not play more than one or two of the short works (each no longer than a couple of minutes) before interrupting himself to contextualize the music or give a bit of its history. The result would have been a charming pseudo-masterclass if Mr Aimard’s playing had sounded more like a pedagogue rather than an overworked student. (It’s no wonder, since he had played two concerti with the International Contemporary Ensemble the day before.)

Most impressive was Mr Aimard’s interpretation of Shadowlines: an uninterrupted 15 minutes of dexterous, assured playing that captured the curious, captivating sound world of its composer. (“I don’t want to get didactic but…” Mr Benjamin joked beforehand, then dived into an explanation of his intricate compositional strategies for the piece.) Mr Aimard unfurled the rapid string of musical processes – one voice following 11 sixteenth notes after the other, for instance – with dauntless persistence and his uncannily intelligent ear. His virtuosity shone through even as the technical processes served to underpin the rich, colorful harmonies resulting from chords that themselves make extreme physical demands of the performer. This was a thrilling rendition of a masterful composition, which managed to look all the more impressive after the preceding 45 minutes of fumbling fingers.

There were nice moments in other pieces as well, though none of them were played as cohesively as Shadowlines. Of the six canons, Mozart’s Modulating Prelude (F major-E minor), K. deest and Chopin’s Prelude in E minor, Op.28 no. 4, played directly afterwards, were most convincingly conveyed; Mr Aimard handled the insane runs of the Mozart with a dexterity absent from the rest of the evening, and then shifted deftly to a beautiful sensuousness during the Chopin. The preceding Baroque preludes, one by D’Anglebert, one by J.S. Bach, took too light of a touch under Mr Aimard’s unsure fingers, which slipped onto a few wrong notes and missed others completely. The unclean fingerwork was evident again during Debussy’s Les soirs illuminés par l’ardeur du charbon and Scriabin’s Prelude, Op.74, no. 4, though Mr Aimard brought to the Debussy a fitting luminous warmth.

Of the etudes, it was Brahms’s Variation no. 6 on a Theme by G.F. Händel that sounded most confident and even at moments breathtaking. Mr Aimard was elegant not just in pianistic execution but in his description as well, saying that the piece sounds like “an organ in a mysterious church”. The canons by Schumann, Bach, and Webern – not to mention Boulez – were less satisfactory, though chaotically-played Webern is always better than no Webern at all. The closing piece of this sequence, Ligeti’s Etude no. 17, À bout de souffle, was, ironically, played extremely well even after Mr Aimard’s claim that it was just as “risky” as the Boulez. His hands flew threw the insane whirlwind canon, which prefigures Mr Benjamin’s piece with its rhythmic and harmonic misalignments, with energy and passion.

Getting didactic during a concert is fine and well, and should probably happen more often, but only if the accompanying performance can live up to (or preferably surpass) the words about it. Unfortunately, this recital was all talk and no action. Rather than ruminations on the connections between the preludes and canons, the only thought running through my mind as I dashed from Lincoln Center was “what would Boulez have said?”