Dorothy Corwin, philanthropist and widow of Los Angeles theater tycoon Sherill C. Corwin, died July 26 of natural causes in Los Angeles. She was 90.In 1924, Corwin came to Los Angeles where she attended Hollywood High and UCLA. She married Sherill Corwin in 1933. She served on the boards of many civic and charitable organizations including Hebrew Union College, the Skirball Cultural Center, Temple Israel of Hollywood, the Los Angeles Music Center and the museum of the Academy of Motion Picture Arts & Sciences. In addition, she and her husband endowed the Dorothy and Sherill C. Corwin Chair in music composition at UC Santa Barbara. She is survived by three children, five grandchildren and three great-grandchildren.