There is more than one artist with this name:1) Petra is a Christian Rock band formed in 1972 by Bob Hartman, Bill Glover, John DeGroff, and Greg Hough. "Petra" means "rock" in NT Greek, making the band name a triple pun. Rising from the Jesus music movement, and initially signed to Myrrh Records, they fought to gain acceptance and recognition in a church culture that at the time believed rock music to be off-limits. Over time they eventually won over most of their critics, thanks to a steady approach and some solid adult contemporary airplay hits like "The Coloring Song," outside of their usual rock fare. By the mid-80's, when lead singer Greg X. Volz left the band and was replaced by John S... read more