On their debut, Mumford & Sons showed that acoustic folk could be played as furiously as rock music. Here, they refine that formula. "I Will Wait" is one of the most satisfying anthems of the '10s—a rush of banjos and harmonies that captures the thrill of young love with just three words. Yet some of Babel's best moments are its quietest, such as the minimal "Reminder", which finds Marcus Mumford singing alone with just an acoustic guitar, recalling the plaintive tenderness of Jeff Buckley.