Music critics take pleasure chronicling the eccentricities of the pianist Marc-Andre Hamelin: his chemistry-teacherlike appearance; his wonkish fervor for the overlooked composerpianists of the late-19th and early-20th centuries; his penchant for letting his spiderlike fingers make mincemeat of the most virtuosic piano runs as he keeps his upper body still.

But while Mr. Hamelin is quirky, he has a particular love and talent for playing mainstream music of the standard repertoire, especially the Romantics. That made him a good choice for the 19th-century masterworks he delivered Friday at the International Keyboard Institute and Festival. (The festival continued at Mannes College of Music until July 25.)

Perhaps fond by now of his reputation, Mr. Hamelin took the stage Friday in a rather unusual outfit: a black,Western-style button-down with blood-red seams and embroidered hearts. I took it to mean that he fancied himself a cowboy about to have some rip-roaring fun with some of the canon’s most mischievous composers.

Take Beethoven,whose first two of his last three sonatas – the Op.109 and Op. 110 – opened the recital.In the Op.109, the most fleetingly poetic of its set, Mr. Hamelin offered a quick, rhapsodic approach that bristled with temperamental energy: Each run had great inner momentum. Throughout the work Mr. Hamelin employed clear,bell-like tones, which made the forceful second movement powerful but never banging. The third movement variations were unfussy and effectively songful.

In this work Mr. Hamelin’s love for extremes – brawny counterpoint contrasted with simple tunes – weren’t deployed fanatically.The result was an articulate reading that could have only been trumped by the most honestly expressive of Beethoven pianists, such as Richard Goode.

Mr. Hamelin’s Op. 110 wasn’t as innocent or effective, even if it, too, impressed. He began this heady work like a fast Mozartian taunt, offering prismatic syncopations in the high-register. But I found his quick second movement too legato, and I was surprised at how little contrast there was between moments of power and soft simplicity.

The third movement adagio and fugue were played freely, cadenzalike. Great control of the piano’s timbres made the performance a sonic feast – at one point Mr. Hamelin repeated the same chord more than five times, giving each articulation another increasingly tense coat of thickness, hue, and gruffness. But the pianist’s penchant for quirky pauses and extreme transitions obstructed Beethoven’s vision a bit. He also missed more notes in these pieces than a player like him should.

Beethoven was one of the first major Romantics, and perhaps that’s why Mr. Hamelin programmed his second half with two of that period’s most recognizable banners: Schumann’s “Papillons” and Liszt’s “Dante” Sonata. The Schumann is a rather easy collection of short character pieces or “novelettes,” and Mr. Hamelin had a distinguishable character for every one – dreamy, neurotic, curious, perturbed. His colorist playing seemed meant for this music.

But the Liszt may be considered the mold on which Mr. Hamelin’s very identity as an artist was made.The “Dante” Sonata is the brash Romanticist’s late epic calling card – a ridiculously difficult array of opium-hazed demonism. At some moments Mr. Hamelin’s softer notes sounded computer-generated. But overall the work was appropriately fantastical and swirling, a passionate, impressive display.

It might have ended there, but Mr. Hamelin didn’t just offer customary encores; he played Beethoven’s complete Sonata Op. 111, the composer’s last and most abstract.This was a somewhat egoistic move – it’s clear the pianist loves the sound of his own voice. It also didn’t give the piece the space it needs to breathe. Mr. Hamelin’s own comments about playing the piece (“for those of you who felt slighted by the program change”) suggested perhaps he had been reined in by his presenters and didn’t want to deny his audience the Lisztian-length concert he had planned.

Not surprisingly, the reading was even more fantasylike than Op.110.Mr. Hamelin presented shocking moments of power in the famously gloomy opening, but then lost himself in superslow evocations of the work’s serene harmonies. It also didn’t help that the Mannes air-conditioning unit had apparently weakened.The piece’s conclusion brought many ovations, but many members of the audience looked as tired and sweaty.The indefatigable Mr. Hamelin, though, did not.