Well, this is sort of the Andy Summers of rock-n-roll documentaries. Congratulations? So reserved as to seem humdrum, director Andy Grieve’s film feels, unfortunately, like a solo act no one really asked for. As filtered through the weakest of three relevant personalities (Sting and Stewart Copeland didn’t participate), here’s the saga of an accidental New Wave trio midwifing the newborn MTV, selling out arenas, squabbling, and inevitably splitting up. Fans may enjoy skimming over Summers’ pre-Police days as a struggling if promising guitarist, but the cursory Can’t Stand Losing You isn’t especially long on musical or personal insights. Finally zeroing in on a style with the infectious arpeggiations of “Message in a Bottle” and “Every Breath You Take,” Summers felt he’d earned himself the privilege to be off romping somewhere overseas with John Belushi instead of nesting on the home front with his own wife and kid. You know how it goes. Grieve has assembled a scrapbook of bleary old footage, and less old footage, from concerts and interviews in which the tetchy trio sat around riling each other up. He lingers over the larky, arty photos Summers took while on tours, but not even a subset of groupie nudes manages to spice these proceedings up very much. Semi-stiff voiceover readings from his memoir One Train Later make Summers sound like a hostage; maybe he was, and still is.