Petra is one of the most successful Christian rock bands ever, a veritable institution whose name (taken from the Greek word for "rock") has come to reflect not only their music, but their staying power as well, even in spite of Christian radio's reluctance to program their brand of loud, slick arena rock. Petra was formed in 1972 by guitarist Bob Hartman, who was attending the Christian Training Center in Fort Wayne, IN at the time; he recruited several fellow students -- guitarist/vocalist Greg Hough, bassist John DeGroff, and drummer Bill Glover -- to his cause, and the gro...