He has done with the sky something similar to what I had done with color before.
-Georgia O'Keeffe to Sherwood Anderson, February 11, 1924
From 1922 to 1931, Alfred Stieglitz turned his four-by-five-inch Graflex camera skyward, resulting in a series of cloud photographs that are recognized as his most abstract and metaphysical expressions. This unnumbered series comprised not a sequence, but a scale of unfolding poetic patterns and tonalities. Seeing their correspondence to music, Stieglitz titled the early images Music, and then Songs of the Sky, eventually naming them Equivalents, to suggest how he saw each image as a powerful equivalent to his innermost emotions and thoughts.
In 1949, when Georgia O'Keeffe was settling Stieglitz's estate, she honored the long friendship between Alfred Stieglitz and Duncan Phillips with a gift of 19 silver prints from the Equivalents series. She wrote, "Stieglitz so often spoke of intending to send them himself. I think they will feel much at home with you."
Many years later in the 1960s, as O'Keeffe took in the expansive sky from a new perspective as she traveled around the world, she felt a similar urge to put down her response in a series of mural-size paintings known as Sky Above Clouds. Two are featured in Georgia O'Keeffe: Abstraction, on view at The Phillips Collection through May 9, 2010.
Alfred Stieglitz, Equivalent. The Alfred Stieglitz Collection, gift of Georgia O'Keeffe, 1949 The Phillips Collection, Washington, D.C.