William Martin Joel is an American singer, songwriter and pianist. Commonly nicknamed the "Piano Man" after his signature 1973 song of the same name, Joel has had a successful music career as a solo artist since the 1970s. From 1971 to 1993, he released twelve studio albums that spanned the genres of pop and rock music, and in 2001 released a one-off studio album of classical music compositions. Joel is one of the world's best-selling music artists and the fourth-best-selling solo artist in the United States, with over 160 million records sold worldwide. His 1985 compilation album, Greatest Hits – Volume I & Volume II, is one of the best-selling albums in the United States.