In 1976, Volz received two of the most important calls of his life. First, he was offered the lead singer position of REO Speedwagon. Volz, being a recently converted Christian, declined. Six weeks later, he got the call to participate in Petra's second album, Come and Join Us. Although at that time he participated as a guest singer in just three songs, founder/guitarist Bob Hartman (who, at that time, was sharing the lead-singing duties with co-founder/guitarist Greg Hough) Huff offered Volz the full-time position.