 Other artists participating on the project include Barren Cross (who debuted the previous year with its Star Song release "Rock For The King") and Mastedon which is the studio project of former Kansas vocalist John Elefante and his brother Dino.Hero was the only band appearing on the album not to go on and make a name for itself.Leading up to the time of "California Metal", Guardian was still in its "space metal warriors" era (the album packaging includes a photo of the band decked out in full body armor).