During this period Prince referred to his band as the Revolution. The band's name was also printed, in reverse, on the cover of "1999" inside the letter "I" of the word "Prince". The band consisted of Lisa Coleman and Doctor Fink on keyboards, Bobby Z. on drums, Brown Mark on bass, and Dez Dickerson on guitar. Jill Jones, a backing singer, was also part of the lineup for the "1999" album and tour. Following the 1999 Tour, Dickerson left the group for religious reasons. In the book "Possessed: The Rise and Fall of Prince" (2003), author Alex Hahn says that Dickerson was reluctant to sign a three-year contract and wanted to pursue other musical ventures. Dickerson was replaced by Coleman's friend Wendy Melvoin. At first the band was used sparsely in the studio, but this gradually changed during 1983.