John DeGroff is a Christian musician. DeGroff was one of the original members of Christian rock band Petra in 1972, along with Greg Hough, Bill Glover and Bob Hartman. He played bass guitar in the band's first two records before leaving in 1979. Petra has been inducted into the Christian Music Hall of Fame (2007), the Gospel Music Hall of Fame (2000), and the Hard Rock Cafe (1994). Also in 2003, DeGroff joined Hough and Glover in a project called "GHF". In 2004, he and Hough rejoined Bob Hartman on stage in a reunion of the original Petra line-up held in Angola, Indiana.