It's been almost seven years since Helmet broke up, and something is missing now that the group has been resurrected without cofounders John Stanier and Henry Bogdan. The constraints set by vocalist and guitarist Page Hamilton have always been so rigid that self-parody was inevitable. But Hamilton still sort of manages to avoid it here. Size Matters isn't simply a retread, but Hamilton lets his muse wander so far into modern-rock territory that he sounds like he's imitating third-generation copycats of his own ideas. It's painful to hear Hamilton generalize his own creative voice or to find that his obscure, poetic lyrics have grown tired, blunt and one-dimensional. Instead, Hamilton should have made the long-overdue album of experimental jazz he's flirted with for years. Helmet fans can handle change, but after seven years out of commission, their band appears to have gone stale.