Meryl Streep's daughter Mamie Gummer is the real star of 'Ricki and the Flash'

Add rock diva to the Meryl Streep Hall of Fame.

In “Ricki and the Flash”, director Jonathan Demme’s first big feature film since 2008’s “Rachel Getting Married”, Meryl Streep plays Ricki, a woman who abandoned her family to follow her dream of becoming a rock star only to end up performing in a dive bar at night with her band The Flash and scraping for cash during the day at a Tarzana, California Whole Foods knock-off. When she gets a distressing call from her ex-husband Pete (Kevin Kline) that their daughter Julie (Mamie Gummer) is suicidal, destitute Ricki returns home to attempt to rekindle a relationship with her neglected daughter.

Streep has the difficult challenge of being a movie star with a character actor's career. As Ricki, it could be very easy for Streep to become a caricature rock persona to the point that we are only watching her play dress-up. But to her credit, Streep immediately immerses herself in the character which translates well on-screen. For the most part, it's hard to see Meryl Streep the movie star as Ricki the failed rock goddess.

Despite being a genuinely sweet film, “Ricki and the Flash’s” tone is rather uneven, which stems from Diablo Cody’s screenplay. The script bounces from Ricki’s bleak rock life to the comically stereotypical suburban life led by Julie and her ex-husband Pete. At times Demme seems to want to drift into a darker, more comfortable area for him, focusing on the dire effects of Ricki's depression and reckless desire to waste her life away. But then on a dime, as if pulled back by unseen forces, Demme turns the film into a sweet little gem as Ricki, Julie, Pete and their sons reconnect over many a mishap, coming moderately close to being too sappy, which thankfully is kept in check.

Then there are the songs. It's one of the more bizarre occurrences in Streep's career to see her belt out Bruce Springsteen live, play guitar and jam around a stage. Jonathan Demme has spent some time since 2008 directing music documentaries – one on Kenny Chesney, another on Neil Young – and it seems that he hasn’t quite shed that style for this narrative film. The movie begins to lag when it spends far too long being a Meryl Streep concert, but those performances do undoubtedly show what an unbridled talent Streep is.

This film does pack a full bag in less than two hours. There's the tunes and some sly comedy of manners -- sometimes overdone -- with poor Ricki's woefully out-of-place look and personality wading through her wealthy family's overly judgmental town – and finally the bittersweet drama between mother and daughter, which is really the heart of the film. “Ricki and the Flash” would be golden if more time was spent on Ricki and Julie’s strained relationship and less on the concert pieces.

The real takeaway from this “dramedy” is Streep's real-life daughter Mamie Gummer's knockout performance. Gummer’s fiery performance as a grieving, yet rebellious, young woman puts her talent and range on full display. Like Streep, she deftly immerses herself into the character and likewise welcomes the audience to join her.

The strong supporting cast is a bonus. The wonderful Kevin Kline adds his usual panache and knack for nailing awkward comedic timing. The camera just adores Broadway star Audra McDonald in her scene-stealing confrontation with Streep over parenting. Rick Springfield really delivers the goods as Ricki’s lover and bandmate Greg. Bouncing from sensitive companion to scorned partner to rocking out on stage in many a duet, Springfield is “Ricki’s” surprising secret weapon.

Overall, “Ricki and the Flash” is a sweet film with solid performances. Will Streep be remembered come Oscar time? Doubtful. But if only one thing should be taken away from this film, it's that the Streep acting genes will surely live on for a long time to come through the superb Mamie Gummer.

Sony/TriStar. Rated PG-13. Running time: 1 hour and 42 minutes.