Filmmaker Marty DiBergi (who bears a striking resemblance to real-life filmmaker Rob Reiner) famously captured “England’s Loudest Band” during its comeback tour in the acclaimed 1984 rockumentary This Is Spinal Tap. Though Spinal Tap fed upon the excesses of success — elaborate tours, groupies, customized amps that go to 11 — the band survived rotating (and one could argue, smoldering) personnel changes, confusing backstage mazes, round lunchmeat, and a knee-high replica of Stonehenge. Today, the founding trio of guitarist/vocalist David St. Hubbins, lead guitarist Nigel Tufnel, and bassist Derek Smalls return to gobsmack a new generation of metalheads on Back from the Dead. Tap show their growth and versatility with updated versions of classics “Hell Hole,” “Big Bottom,” “Sex Farm” (played in the key of funk) and “(Listen to The) Flower People” (done inna reggae stylee). A few artists influenced by Tap — Keith Emerson, John Mayer, Steve Vai, and Def Leppard’s Phil Collen pay respects. Welcome back, direct from hell, where eardrums go to die — Spinal Tap!