Andy Warhol (born Andrew Warhola) August 6, 1928 – February 22, 1987 was an American artist who was a leading figure in the visual art movement known as pop art. His works explore the relationship between artistic expression, celebrity culture, and advertisement that flourished by the 1960s.  After a successful career as a commercial illustrator, Warhol became a renowned and sometimes controversial artist. His art used many types of media, including hand drawing, painting, printmaking, photography, silk screening, sculpture, film, and music. His studio, The Factory, was a well known gathering place that brought together distinguished intellectuals, drag queens, playwrights, Bohemian street people, Hollywood celebrities, and wealthy patrons. He managed and produced The Velvet Underground, a rock band which had a strong influence on the evolution of punk rock music. He founded Interview magazine and was the author of numerous books, including The Philosophy of Andy Warhol and Popism: The Warhol Sixties. He is also notable as a gay man who lived openly as such before the gay liberation movement, and he is credited with coining the widely used expression "15 minutes of fame".  Warhol has been the subject of numerous retrospective exhibitions, books, and feature and documentary films. The Andy Warhol Museum in his native city, Pittsburgh, Pennsylvania, which holds an extensive permanent collection of art and archives, is the largest museum in the United States dedicated to a single artist. Many of his creations are very collectible and highly valuable.