Alexander Calder's standing mobile sculptures represent an innovative fusion of his kinetic mobiles and static stabiles, showcasing his continuous exploration of balance, form, and movement. One of the most iconic standing mobiles by Calder is "Spirale" (1958), a monumental sculpture that stands at 360 inches high and is installed at the Maison de l'U.N.E.S.C.O. in Paris. This piece exemplifies Calder's mastery of scale and his ability to create sculptures that engage with their environment, suggesting motion while being anchored​ (Calder Foundation)​.

Calder's work throughout his career involved a playful engagement with the viewer's perception, where the infinite possibilities within each sculpture's movement and balance could be realized over time or with interaction. His standing mobiles, like all his works, are dependent on the viewer's engagement to achieve their full expression, embodying Calder's belief in the importance of approximation and the dynamic relationship between object, viewer, and space​ (MOMA)​.

"Spirale" and similar works underscore Calder's pioneering role in kinetic art and his contributions to modern sculpture. By the 1950s, Calder had become renowned for his large-scale public sculptures and standing mobiles, which combined the elements of motion characteristic of his earlier mobiles with the monumental presence of his stabiles. These creations were not just artistic achievements but also engineering feats, reflecting Calder's background in mechanical engineering and his lifelong fascination with making art that moves​ (Wikipedia)​​ (MOMA)​​ (Calder Foundation)​.