Starring Meryl Streep. Rated PG. Now playing

Some credible characters and interesting situations pop up in Ricki and The Flash, but the movie just sags when it should soar. That’s disappointing, especially since Philadelphia’s Jonathan Demme directs from a script by Juno scribe Diablo Cody, and it’s Meryl Streep playing an aging rock and roller who got good but not famous, opposite Sophie’s Choice co-star Kevin Kline, no less. So what could be bad? Well, let’s just say that a few cool cuts do not an album make.

Of course, Streep totally nails the persona of a singer-guitarist—complete with blue Telecaster, Marlboro rasp, and tentacular corn-rows—who fled her upper-crust family to almost find her inner Bonnie Raitt. She has a day job, at a Whole Foods-like supermarket, and a regular gig playing souped-up covers to inebriated dozens, at a Southern California bar, backed by real-life, classic-rock musicians including P-Funk keyboardist Bernie Worrell and the late Rick Rosas, Neil Young’s longtime bassist. (The extended music scenes are the film’s most energetic.)

Their lead guitarist is Rick Springfield who, amazingly, will be 66 this month, and this guy’s in love with her. Ricki, however, has commitment issues, but that’s true of the whole movie. Oddly, Cody makes her an Obama-hating, support-the-troops homophobe, and then does almost nothing with this, except to find her mildly awkward around her gay son (Nick Westrate)—although probably no more so than any parent who hadn’t seen her grown children in more than ten years.

Her unplanned family reunion, back home in Indiana (actually upstate New York), follows a call from her ex-husband (Kline). Their recently married daughter is suicidal after getting dumped. While it’s enjoyable to see Streep bantering with her actual offspring, Mamie Gummer, they play a pretty dire situation mostly for cute laughs.

Every subsequent scene of fierce, if witty, dysfunction transpires in snooty restaurants or at the inevitable climactic wedding, for maximum embarrassment. (Sebastian Stan is the other son, marrying a snotty environmentalist.)

The famously liberal director has fun making rich lefties look more uptight than his scruffy, right-wing rocker, and all the extras are instructed to disapprove. It’s not just them. Apparently, we had a chance to get close to this potentially powerful woman, to understand Ricki’s gifts, flaws, and sorrows. But the filmmakers keep snatching away her microphone.