Bristol production duo Massive Attack has never sounded more assiduously live than on Heligoland, its fifth album, and its first in seven years. It’s as if Daddy G and 3D opted to take a cue from their hometown friends in Portishead (some of whose members play here) and reinvent their sound by stripping it bare. But aside from moments like the one where Elbow singer Guy Garvey mumbles over bubbling analog synths and slow-rising horns on “Flat Of The Blade,” Heligoland’s production is largely dry and flat, and the songs tend to disappear once past the strong opening pair. “Pray For Rain,” with TV On The Radio’s Tunde Adebimpe, moves back and forth between near-silence and a rousing, brooding chorus, with Adebimpe at one point exploding, in the background, into a lovely Beach Boys-style chorale. “Babel” features a woody, windy bassline, speedy live-sounding drums, and whining, undermixed guitar howls for Martina Topley-Bird (formerly with Tricky, who got his start on Massive’s 1991 debut Blue Lines) to shade in. The album isn’t bad so much as forgettable—not an encouraging sign in a partnership entering its third decade.