The 13-year wait for Fear Inoculum, the latest album by slithery quartet Tool, seemed borderline excessive—an impious gestation period that promised either an abomination or a glorious new evolutionary stage for heavy-lidded prog-metal. The truth lies somewhere in the middle. The album’s 10 tracks stay the course with unusual time signatures, shuddersome production techniques, and touches of sly humor. At the same time, the canvas Tool is using feels much bigger, as they let musical ideas stretch out and grow and allow for grooves that are easier to sink into and get comfortable within. At least until the knives come out. ROBERT HAM