Lots of time these musicians-turned-actors will surprise you. Case in point: all the rap stars who have made a successful transition to acting. They usually play tough guys, which is admittedly playing to their strengths, but that doesn't mean they don't give convincing performances. Look at Common currently starring on AMC's terrific 'Hell on Wheels' for just the latest example. Some of you may have seen the front gal for Garbage, Shirley Manson, hit it out of the park on a really good little sci-fi show from a few years back - 'Terminator: SCC'.
So don't count out Levine yet. He may be better than you think as an actor, his songwriting and singing abilities notwithstanding.