Sweden's proto power metal sextet Astral Doors offer a sound whose production ideas are rooted in the present, while their crushingly heavy songs emerge from the tropes and schematics of heavy metal history: the pioneering riffs of Black Sabbath, the dark, melodic drama of Ronnie James Dio, the bluesy urgency of Rainbow, and the instrumental flash of Deep Purple. Beginning with 2003's Of the Son and the Father, the Swedes developed a rocking musical persona that offered a logical and exciting continuum in the genre's legacy while also becoming a touring juggernaut. 2010's Requ...