Will we, as a civilization, ever be rid of “The Safety Dance”? It popped back up with the rise of ’80s-themed radio programming, and now it’s a lowlight in this concert flick featuring the cast of TV’s big hit musical series. Three parts semi-celebrity karaoke and two parts feel-good stories, Glee the 3D Concert Movie blends fairly pedestrian production numbers with personal-interest stories of the show’s fans. Unfortunately, the stories, while personal, don’t hold our interest. True, it’s still better than seeing the cast of Glee sing a bunch of other people’s songs without a break—and it’s a well-meaning idea—but the diarists are uninspiring. In terms of the cast, Amber Riley (Mercedes) might have the best vocal performance, while Lea Michele (Rachel) proves she’ll have the biggest breakthrough of the bunch.