Boston band American Authors treats every song as a celebration—their big, anthemic pop-rock is primed for cathartic sing-alongs meant to fill entire stadiums. The quartet powers it all with quick, stuttering rhythms—some that clap and stomp like an old-time hoedown and others that hint at Afrobeat (think Vampire Weekend)—while a sprinkling of banjo and mandolin conjures the folky grandeur of Mumford & Sons. And though the band's songs are mostly biographical, nearly all of them embrace the idea of enjoying the here and now.