In the subdued, mysterious opening of the first movement, Richter plays with bold spaciousness. Forward motion is achieved less from a steady tempo than from sheer suspense. He makes the most of the extreme contrasts between hushed tension and vehement agitation. The perpetual-motion finale, played with eerily controlled wildness, seems at once unhinged and inevitable. He hits a few clinkers in the breathless coda, a problem he cleaned up in a studio recording he made the next month, also included here. I prefer the on-the-edge live “Appassionata.”

In his revealing, sometimes exasperating film, Mr. Monsaingeon milks the mystique of Richter as an enigma, relying on archival footage, including many performances, and interviews. In the opening sequence, as we hear Richter playing the slow movement of Schubert’s late Sonata in B-flat, a text appears: “Richter is a world unto himself, impenetrable yet radiant; a deepwater fish, blind but luminous.” Come now.

Though Richter sometimes speaks with disarming frankness, the film fails to clear up his many guarded recollections of crucial events, some of them shattering, in his life, including his German expatriate father’s arrest and execution for suspected espionage in 1941. Richter’s mother, involved at the time with the man who would become her second husband, refused to leave and flee with the family to safety. Richter’s account is extremely confusing.

Still, the film suggests that as a person, and in the conflicted way he handled his career, Richter was a bundle of contradictions. He decided on the piano relatively late and never considered himself a prodigy. Instead, as a teenager, Richter found jobs playing in factories and nursing homes and became a coach at the local opera and ballet. Yet, when he auditioned at Moscow Conservatory for the pianist Heinrich Neuhaus, who would become his most influential teacher, Neuhaus, deeply impressed, whispered to a nearby student that he thought young Richter a “musician of genius.”

In his maturity, Richter claimed that he never practiced more than three hours a day. Yet in 1943, he gave the premiere of Prokofiev’s Seventh Sonata, one of the most technically challenging pieces in the repertory, having learned it in four intensive days. He also learned and memorized the second book of Bach’s “Well-Tempered Clavier” in a month, an astonishing feat.

During his most active years, he had a repertory of 80 diverse recital programs. Yet he bucked against the protocols of concertizing, which necessitated committing to performances months, even years, in advance. In his later decades, he preferred performing on relatively short notice in smaller halls, which at his insistence were kept dark except for a lamp placed near the piano to illuminate the printed scores, which by that point in his career he routinely used.