Paul Bowles, the American author of “The Sheltering Sky,” died of a heart attack in Tangiers, Morocco, Thursday. He was 88. Bowles, an accomplished composer, was best known for his novels set in exotic North African locales. Bowles was also mentor to several writers, including William Burroughs and Allen Ginsburg. Truman Capote was among those who visited him at his home in Tangiers. As a young man, Bowles studied with composer Aaron Copland and worked closely with Leonard Bernstein. He composed for Broadway musicals during the 1930s and 1940s. His music also was featured in the plays of Orson Welles, Tennessee Williams and William Saroyan.