Judas Priest’s debut only hints at the metal juggernaut the band would soon become. “Winter” and “Run of the Mill” present an odd, but intriguing, cross between the sludge-rock riffage of Black Sabbath (Priest’s Birmingham brethren) and the moody atmospherics of Pink Floyd. Though it was live in the studio, Rocka Rolla features unusually subdued production from Black Sabbath collaborator Rodger Bain, and rockers like “One For the Road” end up feeling strangely deflated. Against the band’s wishes, the 14-minute epic “Caviar and Meths” was edited down until all that remained was the intro, but even in its truncated state the song establishes a model for baroque instrumentals that metal bands would draw from for years to come. Just when it begins to seem that the affable jam band of Rocka Rolla bears no relation to the leather-bound hellions of British Steel, the dueling guitars of “Rocka Rolla” and the operatic wail on “Never Satisfy” are there to remind the listener that the blueprint for Judas Priest’s best work begins here.