A child races giddily from table to table in a crowded café, accepting objects fashioned by the patrons from paper napkins for her amusement. All are lovingly devised and impossibly elaborate: a plane, a bouquet of flowers, a diorama, a kangaroo with a movable tail, the Guggenheim ­Museum in Bilbao, a clown made of “paper so fragile a gaze could tear it.” As each fantasy falls apart in her eager little hands, it is discarded in favor of the next. The concentrated creative aura enveloping the patrons serves as a mere backdrop for her energetic engagement with the moment that keeps turning into the next moment.

This story, “In the Café,” appears early in the Argentine writer César Aira’s new collection, “The Musical Brain: And Other Stories,” and offers a playful example of Aira’s connection with how an innocent operates. He ventures into his chosen café and commits his observations to paper, then swiftly discards the handwritten page. He is at once the patron fabricating delicacies and the child moving back and forth in the stream of what he calls the perpetual present. “The immediate absorption of reality, which mystics and poets strive for in vain, is what children do every day,” Aira writes in the opening story, and it’s a skill he possesses himself. “I can go on inventing indefinitely,” he has said, embracing the incomprehensible with such compassionate delight that the incomprehensible begins to comprehend itself.

Aira’s cubist eye sees from every ­angle. Again and again in these stories he confronts the classic mathematical challenge known as the paper-­folding problem, which suggests a piece of ­paper can be folded in half only nine times. Not bound by the practical limits of this folding sequence, Aira envisions ­another algebraic possibility. In “Picasso,” an O. ­Henry-style tale, he not only paints a picture of who Picasso was and his place in art history, he also provides a majestically perceptive description of an imagined work of art: “The queen, composed of so many intersecting planes she seemed to have been extracted from a pack of cards folded a hundred times over, refuting the proven truth that nine is the maximum amount of times a piece of paper can be folded in half.”

The stories in “The Musical Brain” exhibit the continuing narration of Aira’s improvisational mind. His characters — whether comic-strip ruffians, apes, subatomic particles or a version of his boyhood self — enter a shifting and tilting landscape of events that unhinge our temporal existence and render it phantasmagorical yet seemingly everyday in the unfolding. His matter-of-fact approach, accepting even the most outlandish episodes, suspends disbelief and encourages one’s own sense of displacement, of being released from the commonplace.