On paper, James Murphy producing songs for Arcade Fire sounded so ideal, there was almost no chance it wouldn't suck.Then came the promising title track from Arcade Fire’s Reflektor. Lo and behold: proof positive that the former LCD Soundsystem knob-twirler can tweak another band’s sound and put his own stamp on it, without making unrecognizable. What that means for The Roots is that having Murphy behind the boards wouldn't automatically result in post-punk-inflected hyper-disco rap; just something danceable. And definitely with bongos.