Mumford & Sons

For a band that started out relying mostly on acoustic instruments and barely any drums, Mumford & Sons fashioned a mighty big sound from the get-go. They could be regarded as folk-rockers, but the band—formed in West London in 2007—harness the kind of passion, power, and inspirational drive usually associated with the likes of U2. Main man Marcus Mumford and his cohorts Winston Marshall, Ted Dwane, and Ben Lovett (all of whom play multiple instruments) began building their following from the ground up in and around London before releasing a string of DIY EPs and finally earning enough attention for Island Records to release their debut album, Sigh No More, in 2009. In an electronic-saturated pop era, that record's blend of back-porch picking and arena-ready presence leaned un-self-consciously in the opposite direction, invoking their native folk traditions as well as those of the U.S. But it was 2012 follow-up Babel that really cemented Mumford & Sons' star status. Its first single, the banjo-charged, passionately swelling "I Will Wait," became an intercontinental smash, and the folk-rock floodgates opened. The band's success cleared a path for kindred unplugged spirits like The Lumineers, but by the time Mumford & Sons released their third LP, 2015's Wider Mind, they'd already evolved into another phase, tamping down the folk and amping up the rock, a process they further refined over the next three years, achieving an even more widescreen sound on Delta.