Leslie West began his musical career in the Vagrants, a teenage R&B band. Felix Pappalardi, sometime producer with Cream, also worked on some of the  Vagrants'  records. This lead to support slots with big acts like Cream and the Who. In 1969 Leslie West went on to form the rock group Mountain with Pappalardi on bass/vocals, the drummer Corky Laing and keyboard player Steve Knight.