On paper, the idea of a multiracial, emo-hop-'n'B quartet who team up with a slew of guest stars sounds pretty great. And there are moments on Gym Class Heroes' fourth album when their sound lives up to that concept: "Guilty as Charged" features a rippling, brass-propelled chorus with a terrific vocal turn by British diva Estelle. The-Dream drops by for two saucy songs, the double-entendre-packed "Cookie Jar" and "Kissin' Ears," which dispenses with euphemisms altogether. But there's a big problem here: Travis McCoy, the band's six-foot-five MC. The Quilt finds him pouring out clunker couplets ("Papa was a rolling stone/But I want to be the cover of a Rolling Stone"), lame boasts ("Guilty on all charges for the dopest album of the year") and odes to his lothario-level texting skills ("It's like fishin', my words are like lures") in a rap style embarrassingly modeled on Eminem's — without the wit. It's no coincidence that the album's standout song is "Live a Little," a power-pop melody bomb written and sung by guitarist Disashi Lumumba-Kasongo.