On TV, Adam Levine can be funny, spontaneous, unafraid to come across as the irritating truth-teller, full of feisty repartee with bro-rival Blake Shelton. As the frontman for Maroon 5, the L.A. band best known for smash earworms from "This Love" to "Moves Like Jagger" to "Payphone," Levine is the falsetto-bot who submits to a hitmaking formula that is getting more rigid with every album.