Joan Miró was a small, fastidious, taciturn Catalan. Alexander Calder was a big, rumpled, gregarious American. At first glance, they would appear to hail from distant planets. Yet once they met in Paris in 1928, they enjoyed an unusually close and mutually beneficial friendship that lasted until Calder’s death in 1976. With other artistic pairs, like Pissarro and Cézanne or Picasso and Braque, competitiveness ignited and acrimony at times soured the creative ferment. But Miró and Calder unfailingly championed and nourished each other’s work. A principle that Calder applied to his art could also describe their relationship: “Disparity in form, color, size, weight, motion, is what makes a composition.”

Pace and Acquavella Galleries team up next April to present "constellation" works by the two artists

Mr. Rower also said that dual exhibitions of works known as “constellations” were coming up next spring. Pace gallery will show Calder’s “Constellations” series in wood and wire, which he made in 1943, and Acquavella will show Miró’s series of 23 tempera “Constelaciones” paintings, done from 1940 to 1941 and exhibited by Miró’s dealer, Pierre Matisse, in New York in 1945.

Calder’s “Constellations” series was given its title by Marcel Duchamp (who also named the “mobiles” in 1932) and the critic James Johnson Sweeney; Miró’s were named by André Breton, the father of Surrealism.

“Both bodies were made by these two guys, but neither of them named these bodies of work ‘the constellations’ themselves — they were named by other people,” Mr. Rower said.

“If you can project yourself back in time and do this kind of in-depth research,” he continued, “you discover something that’s really quite surprising.”