Rob Frazier
In 1979 he joined the Christian rock group Petra , where he played the keyboards and guitar while trading lead vocal duties with Greg X . Volz on the album "Washes Whiter Than" . 
<triplet> Petra <subj> Christian rock <obj> genre <triplet> Greg X. Volz <subj> Christian rock <obj> genre <triplet> Washes Whiter Than <subj> 1979 <obj> publication date <subj> Petra <obj> performer