MAROON 5  singer ADAM LEVINE is working on another project with NBC...where he already serves as a coach on The Voice".

He's developing a sitcom set in a karaoke bar that will "blend comedy with vocal performances."  It's pretty early in the process . . . so there's no word on a title, an airdate or casting.

Adam is an executive producer on the project, and at least for now, there's no indication that he'll actually appear on the show.

Adam hasn't commented on this.