Who could blame Mumford & Sons for running away from their signature banjo stomp? Come 2015, when Wilder Mind saw spring release, so many bands had copped their big-footed folk jamboree that Mumford & Sons could feel the straitjacket constricting, so it's not a surprise that the group decided to try on something new. Without their old-timey affectations, they wind up sounding like handsome AAA rockers with a debt to U2, a group that masters sound over song. They do swing for arena-filling hooks and connect — the quietly escalating "Believe," the incessant surge of "The Wolf," "Ditmas," which is the only song here that would scale to bare-bones acoustic arrangements — but usually they subsist on a simmer, letting their immaculate, tasteful rock bubble quietly. Often, the persistent, moody murmur recalls a diluted Kings of Leon, a comparison that underscores how Mumford & Sons have made the journey from retro throwback to glistening modern construction.