Mogwai’s signature has always been a love of pure sonic pleasure, emphasizing the peaks and valleys of song structures via repetition, sequential layering and overbearing decibel levels. Songs longer than 10 minutes work best, allowing the melodic ideas to stretch themselves out to greater poignancy. Mr. Beast may come as surprise—most tracks are short, perhaps to see if the same effect can be achieved in less time. That works best—on “Acid Flood,” where a pedal steel kicks in at the outro, and the tight searing guitar blast of “We’re No Here”—when the band finds ways to make wonderfully unexpected statements that pleasure in their surprise effect.