Of the varied outfits who came to define noise rock in the early ‘90s, Helmet were arguably the most commercially successful, and certainly one of the most influential on the wider landscape. Dissonant and direct, their staccato riffage and driving drumbeats inspired countless post-hardcore bands and, via mega-fans Deftones, inadvertently laid the foundations for nu-metal. Thirty-odd years since their classic albums Meantime and Betty, can these veterans still channel such seminal sonics? Sadly, the answer is no. Any time something on ninth album Left threatens to quicken the pulse – the odd decent riff on Bombastic or Dislocated, for example – it’s swiftly subsumed by the sense of a band trudging through the motions. Where once Helmet seemed to move to their own unique internal...