WindMaster windmills served as the cover of Unseen Power. WindMaster was an energy company in the United States. They provided Petra with the location for the cover of their album Unseen Power. The process was handled by William A. Chapman. Retrieved from "https://petra.fandom.com/wiki/WindMaster?oldid=5898" Categories: Add category Cancel Save Community content is available under CC-BY-SA unless otherwise noted.