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 group began playing around the Fort Wayne area with backing from their school. Petra encountered early resistance to the very idea of Christian rock from many local churches, who held that the rock & roll sound was inherently evil; nevertheless, the group proved popular with younger Christians, and was signed to the Word Records subsidiary Myrrh in 1973. Their self-titled debut was released in 1974, and was more similar to the California country-rock of Eagles than to the arena rock that would dominate most of their career. The follow-up, Come and Join Us, did not appear until 1977, but it featured strong contributions from lead vocalist Greg Volz, as well as a harder-rocking sound.

Petra's lineup fluctuated over the next several years; in spite of the instability, they managed to record their first breakthrough effort, Washes Whiter Than, in 1979, which featured the Christian radio hit "Why Should the Father Bother." When the dust finally settled, the group consisted of Dan Hartman, Volz, keyboardist John Slick, bassist Mark Kelly, and drummer Louie Weaver. The albums Never Say Die! (1981), More Power To Ya (1982), and Not Of This World (1983) did much to popularize the group, and in 1984, they were rewarded with a Grammy nomination for Best Contemporary Gospel Group and two Dove Award nominations (the first of many). For 1985's Beat The System, ex-Joe English Band keyboardist John Lawry replaced Slick. In 1986, Greg Volz left Petra for a solo career, and former Head East singer John Schlitt assumed vocal duties for Back to the World. 1987's This Means War marked a successful transition to a less polished brand of rock & roll. Subsequent efforts, like 1988's Room on Fire, which debuted bassist Ronny Cates, brandished a heavier guitar onslaught in the wake of Stryper's success as a Christian metal band, although Petra never neglected their trademark lush ballads. Petra has soldiered on through the '90s and into the 2000s with few signs of slowing down. 1995 saw Lawry replaced by Jim Cooper, and the addition of guitarist David J. Lichens. Subsequent efforts include 1998's God Fixation and 2000's DoubleTake: Tree63. ~ Steve Huey, Rovi