Ibrahim El-Salahi has long been a modernist force in Arab and African art. He was born in Sudan in 1930, studied in Britain, and then returned to Khartoum, to teach at the College of Fine and Applied Arts. His teaching sparked a movement—the burgeoning Khartoum School, which pioneered the Hurufiyya aesthetic. Like the school he founded, El-Salahi’s work combines Arabic calligraphy, Surrealist figuration, and geometric abstraction in canvases that reverberate with power. Now 91, El-Salahi has grown tired of large-scale works. He channels chronic pain by drawing on the back of pill bottles, envelopes, and scraps of paper. In the last two years, he’s finished 300 drawings. One hundred are on view in this show, El-Salahi’s first in a museum since his 2013 retrospective at Tate Modern. —E.C.