According to the photographer Edward Weston, Galka Scheyer was “the ideal ‘go-between’ for the artist and his public.” Born in 1889 in Braunschweig, Germany, and named Emilie Esther Scheyer, she studied painting in Paris, London, and Brussels. In 1916, Scheyer met the Russian artist Alexei Jawlensky who gave her the nickname “Galka”—Russian for a type of jackdaw (a species related to crows)—and introduced her to the group of artists she called the “Blue Four.” These figures, which included Lyonel Feininger, Wassily Kandinsky, Paul Klee, and Jawlensky himself, were united under her management. She worked tirelessly to promote their work and was vital in bringing European modernism to the U.S. This exhibition at the Norton Simon Museum showcases portraits given to Scheyer, and also includes glowing correspondence from her colleagues. —Maggie Turner