Thunderous blues-rock and cinematic folk from a rising Icelandic quartet. Produced by Jacquire King (Kings of Leon, James Bay), A / B is an uncommonly commanding album, as powerful in its ballads (“All the Pretty Girls,” “Save Yourself”) as in its high-proof distillations of roadhouse blues (“Glass House”) and Allman-style grit (“Way Down We Go”), or in finding a balance between tough and tender on the twangy standout “Automobile.”