Exuberance, sincerity, melodrama, banjos—everything that led to Mumford & Sons' rise to superstardom is here on their 2009 debut. Animated by rich harmonies, lightning-fast picking, and epic crescendos, tracks like "Little Lion Man" and "The Cave" defined the arena-folk sound the Sons popularized. On the album's tempestuous opening track, Marcus Mumford exclaims, "Love, it will not betray, dismay, or enslave you/It will set you free." That's the band's guiding ethos, teed up right from the start.