The stage of Davies Symphony Hall was disarmingly blank. The sight, typically bathed in warm light with rows of chairs and tightly packed instruments, stood tabula rasa March 31 — save for a sleek, expectant Steinway.

Only Bach could lure Lang Lang to the Bay or, more dauntingly, to the Baroque. The Chinese pianist holds a coveted level of celebrity, known for his sparkling showmanship and Romantic war horses. A Baroque program, in all its restraint and measure, is atypical to his repertoire, but there’s a sense of mania in “Goldberg Variations.” Its varying harmonic schemes, distinct styles, and sweeping sophistication begs for interpretation and is too tempting to resist. Besides, Lang Lang may be one of the few performers able to make circa 80 minutes of G major worthwhile.

The composition opens with an aria and splinters into 30 pieces — a gnarled web of bass line, technique and meter. Lang Lang entered the stage pruned of frills and pretense, sporting an inky suit as he quietly bowed and took his perch at the bench.

Lang Lang unspooled the opening melody with masterful voice work. The aria’s metrical confines loosened as the sarabande luxuriated in rhythmic freedom. His sparse pedal work melted lyrical passages and let them run like water. Yet, the aria’s polyphony shone with the clarity of a pool reflection; overlapping, ornamented melodies were seldom left to drown in the pianist’s show of passion.

Lang Lang approached Bach’s musical homecomings with a reverence that teetered on indulgence, taking his time to wring out cadences and phrases like a sweat-soaked towel. Perhaps a relic of his Romantic penchant, theatricality flickered in subtle moments — the jolt of his arms, the toss of his head, the slink of his wrists mimicking the aria’s falling end.

The aria waded through a more contemplative mood than its subsequent variations. Lang Lang invigorated the initial, uptempo pieces with brio and bravura. He breezed through Bach’s tightly wound exercises in miniature with astonishing ease. The fluttering turns carried a sense of levity and playfulness, buoying a style of playing so symmetrical and technically challenging that it can, in the wrong hands, quickly become rote.

Lang Lang plays with cosmic virtuosity. The melancholic variations, such as 15 and 25, moved like the slow rotation of an icy planet, expressive and aching. Variation 25, however, seemed buried under gloom. The pianist stretched Bach’s cantilena like taffy, but labored fermatas and rubato let the planet freeze over. It’s an Achilles heel far less fatal in live performance than, for instance, in Lang Lang’s controversial recordings of “Goldberg Variations.”

Austrian pianist Artur Schnabel wrote that the nature of a performance “is to happen but once, to be absolutely ephemeral and unrepeatable.” Schnabel underscores a preciousness in the evanescence of live performance. A similar reverence washed over Davies Symphony Hall, and any questionable stylistic decisions — or pauses to put in eyedrops — ebbed into a blase ripple, subsumed by the bewitching performance.

In his element, Lang Lang is a supernova. He thundered at the piano, hands striking the pompous chords of Variation 29 like Zeus’ thunderbolts. The scintillating variations, such as 14 and 28, whirled with pin-sharp clarity. Variation 26 was set to a breathless, joyful tempo, and Lang Lang fanned the fire with inexhaustible passion. He played with such ferocity and precision that the rapid, undulating melody seemed to leave smoke in its path.

Yet, when the fumes faded and the twirling variations slowed to a stop, Lang Lang coaxed glassy softness from the piano — a supple sound, gentle but grounded. After summoning violent storms in expansive leaps, Lang Lang returned to the aria delicately, treating its melody with the gentleness of morning dew.

Bach’s “Goldberg Variations” unspooled leisurely at Davies Symphony Hall, but Lang Lang surprised the ravenous audience with an encore performance of “Jasmine Flower,” a popular Chinese folk song. The encore shrugged off pretense and embraced vulnerability. Lang Lang glittered in “Jasmine Flower,” the pentatonic melodies fluttering around the hall’s ethereal chrysalis. A sense of magic buoyed patrons as they left Davies’ cocoon, greeting the chilly San Francisco air tender-hearted and transformed.