Sets of variations seem to hold particular attraction for musicians of questing intellect. One such inquirer, pianist Hung-Kuan Chen, devoted his recital last night at the Foundation for Chinese Performing Arts Annual Music Festival at the Walnut Hill School to a pair of compendiums: Beethoven’s op. 120 Diabelli Variations and Brahms’s op. 35 Paganini Variations. Chen, formerly a teacher at the New England Conservatory, currently at Juilliard and Yale, and whose program biography hints at polymathic tendencies (baking, woodworking, and dance are among his cited enthusiasms), turned the match between genre and practitioner into an evening-long contemplative trek, pensive and vigorous in turn.

Chen gave Beethoven’s 33 Diabelli Variations, that majestically quirky monument, a thoroughly physical performance—not in the sense of being athletically demonstrative, but with each idea primarily considered in light of the necessary physicality of its realization. Often, the impression was of the physical conception governing the sound, instead of the other way around. Chen’s rubato was as much a function of the momentum of his hands as an expressive spotlight. The trills and turns of the 6^th variation became the main and driving point, rather than decoration. Chen pedaled each and every stabbed chord in the Presto 10^th variation, his foot, his hands, his whole body fluttering in the music’s stiff, swift breeze. The drumrolls in the 22^nd variation seemed to originate from Chen’s thrown elbows; he pounced on the Vivace triplets of the 27^th with kitten-ish paws. It wasn’t all density and speed: a keenly still Andante 30^th variation set up a tidal undertow in the 31^st ’s Largo. But, fast or slow, the physicality left Beethoven’s volubility and even awkwardness intact, emphasizing the angularity of the music rather than finessing it.

Introducing the work, Chen attributed its comparative rarity on concert programs to its duration, but the hour went by quickly. One might imagine performances of more dash or splendor, but I can’t recall one in which each phrase had been so fully and thoughtfully considered, and then reconsidered in real time, buoyed by the constant fizz of Chen’s intellectual engagement.

With the Brahms, the mood shifted from experimental intrigue to confident entertainment. Chen remarked on the opposites-attract incongruity of the “devil” Paganini and the “young saint” Brahms; his performance proceeded to side with the angels, not least with a more prominent halo of pedal cushioning much of the music. The score might be more technically inclined than Beethoven’s—each etude-like variation working out a single virtuosic conception—but Chen’s interpretation was geared toward those traditional piano-showpiece aims, expressive elegance and brio. Chen rounded off phrases with tempered, tasteful assuredness. Fast sections were dispatched with high-wire derring-do, more lyrical passages were judiciously milked for heightened sentiment.

Chen offered only one encore, but an exceptionally generous one: the slow movement of Franz Schubert’s final, Piano Sonata in B-flat Major (D. 960), played as if with a single, long, exhaled breath. After the night’s journey the effect was rather like an explorer, at long last, anchored in port.

Matthew Guerrieri regularly writes on music for the Boston Globe; his writing has also appeared in such publications as NewMusicBox, Vanity Fair, The American Scholar, Playbill, and Musical America.