Boston audiences surely know that Jeremy Denk is one of the most intelligent, interesting and superbly equipped pianists anywhere today; I discussed him a couple of years ago in these pages when he played Ligeti’s Etudes and the Bach “Goldberg” Variations at a Gardner Museum concert, and I especially treasure his recording of Ives’s Sonatas 1 and 2. On Saturday night in Jordan Hall, as part of the Celebrity Series, he certainly didn’t disappoint. It was an unusual program, as I will explain.

Bartók’s only Sonata for solo piano, dating from 1926, is seldom heard on recitals, but it’s one of his best works. The motoric repeated-note style of the first movement takes up where the very popular Allegro barbaro (1911) left off, and the third movement expands on this with the percussiveness that Bartók later developed in more familiar works like the Sonata for Two Pianos and Percussion and the Music for Strings, Percussion and Celesta. In between is a slow movement that despite its tonal gloom and dissonant chorale-like chords can even be called expressive. (It was only three years earlier that Bartók had met Henry Cowell in London and heard him play some of his cluster pieces; he asked him for permission to make use of the same kinds of sounds, which of course Cowell was delighted to grant.) It was wonderful to hear Denk play this big piece with the flamboyance it deserves, and it was obvious from his gestures that Denk was enjoying himself too.

A fascinating group of Liszt pieces completed the first half of the program. The “Weinen, Klagen” Prelude began it. (This is not to be confused with Liszt’s Grand Variations on a Bach theme, which is a much bigger work; yet both begin with the sighing chorus in Bach’s Cantata 12, over a descending chaconne bass that Bach later used in the Crucifixus of the B minor Mass.) This was followed by the Sonetto 123 del Petrarca from the Années de Pèlerinage, Book II, from 1839. This barcarolle-like nocturne resembles the more popular Liebestraum but is much more subtle; it forms a significant inspiration to the generation of the Russian “Five” and to Rachmaninoff after them. Denk moved without pause to the last item of Book II, Après une Lecture de Dante: Fantasia quasi Sonata, a sprawling, noisy, harrowing work that ascends inexorably from “Inferno” to “Paradiso” even though these aren’t indicated, with plenty of tritone-related motives and harmonies (the piece begins with octaves moving down in stark tritones). The Dante Sonata, as it is usually called, is like a preliminary exercise for what culminated in the great Sonata in B minor of 1854, and the resemblances are often strong. Denk made the most of the Dante Sonata’s strengths, which are considerable, even though the piece is about one-third too long. What I found most satisfying about his performance is his ability to get a big, grand sound appropriate for the piece but without the usual banging that one hears in performances of Liszt by Horowitz and lesser masters. This also maximized the contrast with Denk’s pianissimo sound, which is equally sensitive and compelling whether in quiet cantabile or jeu perlé filigree.

Denk’s gesture of triumph at the end of the Dante was greeted with cheers, but I’m not surprised that he bowed and then left the stage just to catch a breath before returning for the last Liszt offering, the “Liebestod” from Wagner’s Tristan und Isolde. This begins with a four-measure “Liebeheiligstes Leben” motive, just before the first bars of “Mild und leise.” (They are not thus juxtaposed in the opera.) It was then that the subtle tonal planning of the Liszt group became apparent: the “Weinen, Klagen” Prelude in F minor, leads to the Sonetto in A-flat major as relative minor to major, and the “Liebestod” returns to A-flat major, but the tritone of A flat and D at the beginning of the “Liebestod” relates to the end of the Sonetto and the end of the Dante, which began with the opposite tritone (A and E flat). It sounds like a complicated relationship but the ear understands it more easily than I can explain it.

After the intermission there was another subtlety of programming: the 24^th Prelude and Fugue from Book I of Bach’s Well-tempered Keyboard. Walter Piston’s Harmony eloquently treats this pair, pointing out that the characteristic dissonances in the Prelude are prepared (passing tones, suspensions), whereas those in the Fugue are unprepared (appoggiaturas approached by skip). The Fugue has been called a “twelve-tone fugue” because all twelve pitch-classes are included in its stark, angular subject.

The connection is in the appoggiatura motive, with sighing semitones, which is exactly like the “weeping, lamenting, worrying, quaking” of Cantata 12. The fugue subject is, after all, undeniably weird, the more so because it contrasts, in its four-part fugal development, with very plain and plodding harmonic sequences such as one would find in some minor work by Corelli or Vivaldi. But the contrast is a major part of what one loves about this piece.

Jeremy Denk concluded his program with Beethoven’s Sonata No. 32, op. 111, and one could relate its function in the program to the earlier pieces by its abundance of diminished-seventh harmony, including the thunderbolt gesture in the first bar. One wonders if Chopin, who professed a lack of understanding of Beethoven, was thinking of this stormy piece when he wrote his Etude, op. 10, No. 12 (the so-called “Revolutionary”), in the same key. It was apparent to me that Denk was a little tired by this point in the program, because there were some parts that despite the passion were slightly unclear. But he recovered nicely in the famous Arietta variations, Adagio molto semplice e cantabile, with their strange mensural proportions and changing meters (9/16 to 6/16 to 12/32 to 9/16) and the fine serenity of the long last variation. Most of us who have struggled to play this work recognize that Beethoven, who was thoroughly deaf when he composed it and had been for several years, probably had to guess at the limitations of piano sound and register, especially when the hands are several octaves apart. Like Chopin, Beethoven sometimes composed for an instrument that didn’t exist anywhere except in his mind.

After a standing ovation, Denk returned to play one encore, Bach’s 13^th Goldberg variation, taking the repeat of the second half but not the first. It didn’t matter, a friend said to me afterward, because after all he played it so romantically.

Mark DeVoto, musicologist and composer, is an expert in Alban Berg, also Ravel and Debussy. A graduate of Harvard College (1961) and Princeton (PhD, 1967), he has published extensively on these composers and many music subjects, most notably,  harmony.