As one of the legendary acid casualties of psychedelic rock, it once seemed unlikely that Roky Erickson would ever make a triumphant comeback, the way such other damaged ’60s legends as Brian Wilson have. Roky, of course, never completely went away, continuing to record into the ’90s and experiencing periodic revivals, but he’s never had a full-fledged, well-oiled comeback as he has this past year in the wake of the release of a feature-length documentary about his life. The Explosives, the band that has been working with him sporadically since 1979, has taken him on a tour that’s run through the European festivals and made it here to Bumbershoot this Labor Day weekend, and they certainly should take a good deal of credit for making this the hardest-rocking set heard at this three-day festival Certainly, the Explosives’ guitarist is leading the band, playing a lions share of the leads and taking over stage-patter duty for Roky, whose only words to the crowd were spirited variations on “Thank you!” This ceding of the spotlight and repetitive appreciation was enough for anybody that knew something was wrong to think that Roky might not all be there, but if you didn’t know anything was wrong with Roky, you’d never know from his performance, which was vigorous and vital. A big guy with long stringy grey hair wearing a blazing green Hawaiian shirt, he looked different from the rest of his sharp-dressed band, the only one that might have been a true refried 60s icon, but he sounded lucid and loud, belting out his cult classics with genuine passion. And it wasn’t just that he sang with gusto, he played some mean guitar, especially on a couple of crawling 12-bar blues, including a take on Bo Diddley’s “Before You Accuse Me.” There was no warming up for the Explosives — they came roaring out of the gates and once they locked into “Don’t Shake Me Lucifer” on the third song, they had already reached cruising altitude and they maintained that peak throughout their relentless set, which naturally closed with “You’re Gonna Miss Me” (strangely enough, the only tune hurt somewhat by an instrumental muff as the opening chords didn’t hit as hard as they should) and extending through an encore (rare at Bumbershoot) that concluded with “I Walked with a Zombie.” By that point, it was clear that Roky has rejoined the living and that fact is a cause for rockers of any age to celebrate.