With songs that mixed heart-on-sleeve sincerity, sarcastic humor, and killer pop-punk hooks, Fall Out Boy brought emo aboveground in the '00s. After years of underground touring, the group's 2005 sophomore album, From Under the Cork Tree, transformed them into arena-filling rock stars, and Fall Out Boy quickly developed a new musical ambition to match. Later albums like 2008's Folie à Deux and 2013's Save Rock and Roll buzz with glam-rock riffs, synth-pop melodies, and R&B grooves—a surprising development for four guys who started out playing hardcore punk.