Larry Rivers became an artist in the 1940s, and was soon part of a New York avant-garde scene of dancers, musicians and writers. A saxophonist-turned-painter, he refused to adhere to any genre, and his puckish work has an air of jazz improvisation. He’ll be celebrated at (RE)APPROPRIATIONS, an exhibition spanning five decades of his work at the Tibor de Nagy Gallery in New York from 6 September