Travie McCoy: "Dr. Feel Good"

A sticky-sweet summer confection if ever there was one, this highlight from Gym Class Heroes frontman Travie McCoy finds him teaming up with Gnarls Barkley's Cee-Lo Green and dishing out whipcrack, mile-a-minute raps between Lo's high-gliding, R&B vocal hook. "Dr. Feelgood" is a brisk, funky number, punctuated by tight guitar stabs and bright blasts of organ. Considering McCoy's addiction to painkillers, which he's since kicked, it's a bit odd to hear him rapping, "She's got a set of lips like a sedative/and every time I kiss, it's like medicine." Who's the femme fatale who could inspire that conflicted analogy?