NEW YORK, NY.- On Wednesday night at Carnegie Hall, pianist Vikingur Olafsson’s performance of Johann Sebastian Bach’s “Goldberg” Variations had everyone in a trance — including him.

Playing from memory in his debut on Carnegie’s main stage, he swayed in a gentle reverie and hunched over the piano so intently that he almost touched his forehead to the keys. After the final movement, audience members applauded robustly as they got up to stand shoulder to shoulder. But hardly anyone moved to leave.

The “Goldbergs,” which Bach “prepared for the soul’s delight of music lovers” according to the score’s title page, employ a circular logic. A graceful aria in the style of a sarabande goes through 30 variations. Each movement has two sections, and each section repeats once. Every third variation is a canon — itself a looping form — and the whole, massive work closes with the same aria that started it. The variations, all but three in the same major key, utilize roughly the same harmonic progression, so listeners are lulled by the shared cadence but also dazzled by the inventiveness that masks it. The overall effect is mesmeric.

It’s a 75-minute summit of the piano literature, and Olafsson gave a spectacular concert of it. He already has an elegantly accomplished recording of the piece, and a live setting only revealed new layers in his interpretation: intensely emotional and intelligently paced, immaculate in its technique and organic in its phrasing. It was an artistic feat of contradictions that, in the end, felt deeply human. As he told The New York Times in the fall, “Bach is not one thing; he’s everything at the same time.”

With a malleable, mellow tone and bouncy bass lines, Olafsson was true to his word, exploring a tension between introversion and extroversion and giving each piece a dynamic topography.

Olafsson seldom, if ever, played a section the same way twice. A repeat could recede into or explode out of itself as he pulled the bass line forward with emphatic stomps or reduced the top-line melody to an introspective twinkle. An inner voice might surface for a bar or two before retreating back into the musical fabric.

In molding each variation, Olafsson exercised a modern piano’s capabilities. Rubato in the 13th Variation and subito piano effects in the 12th gave shape to quick figures that might otherwise pass mechanically. He applied a luscious, pedal-assisted legato to the notes of a melody in the 11th, and slightly detached them in the Ninth. The written-out trills of the 28th Variation effloresced with a mild gleam, and the fughetta of the 10th hit the ear with a tonal wall of sound. Olafsson’s pedalwork sometimes smudged the notes: The neat-as-a-pin figurations at the top of the 27th Variation almost turned into glissandos by the end.

Most impressive of all was Olafsson’s sense of architecture. He strung together variations without pause into a frictionless perpetual-motion machine. One such sequence passed through the breakneck minuet of the 19th, the controlled delirium of the 20th and the clean, shiny descents of the 23rd to culminate in the famous 25th, the so-called black pearl. This meditative adagio is the work’s longest movement, and Olafsson stretched its darkling arabesques to more than 10 minutes. But it was wholly engrossing — a private, lonely thought keeping its own company.

Then, Olafsson blazed into the sequence that climaxes with the celebratory festoons of the 30th and final variation, the Quodlibet, which joyously weaves together strains of melody.

Of course, the Aria returns. At the beginning of the “Goldbergs,” it shyly peeked out from the dark and gradually fortified itself. For its farewell, Olafsson played it more fluidly, but also with more confidence in the rightness of its hermitage. Without joy or sorrow, the Aria waved goodbye as it receded from view, gently releasing Olafsson and the audience from the work’s spell.

This article originally appeared in The New York Times.