A lot of sentiments, ranging from “greatest actor of our generation” to “she can do anything” are regulary associated with Meryl Streep. She’s one of the most definitive, well-known and widely-respected members of Hollywood royalty, and fans have come to expect full commitment from every performance she gives.

Still, when one hears about Ricki and the Flash (2015), where she plays an aging rock star who returns home to rekindle relationships with children she’s largely ignored, it inspires some wonder: Can Meryl pull this off? Will this be the one role that just doesn’t suit her?

As it turns out, response to her character has been largely positive. The reason? - Because Meryl Streep, through her famous dedication to bring everything she can to a character, truly learned what it means to be a rocker. We already knew she could sing (Postcards From the Edge (1990), Mamma Mia! (2008), Into The Woods (2014)), but for Ricki and the Flash, she learned how to be in a band and present herself as a genuine rock performer. In Ricki, Meryl does her own singing and guitar playing.

“Meryl developed and created this character: her musical personality, the way she moves, the way she dances on the stage, the way she plays, all that stuff is 100 percent pure Meryl Streep.” - Director Jonathan Demme, Entertainment Weekly.

The music in Ricki and the Flash was recorded live, requiring Streep to learn how to play the electric guitar, and be able to keep up with the likes of authentic rockstars and film co-stars Rick Springfield and Rick Rosas. In fact, the production pushed back the start date of filming in order to afford her more time to learn how to play guitar. Streep took three months of acoustic guitar lessons, then moved onto electric for another couple months. Her instructors have not all been publicly revealed, but given that one was longtime Jonathan Demme-collaborator Neil Young, it’s easy to grasp the caliber of guitarists with whom she worked. Meryl also discreetly visited bars and other live music venues to study musicians in their natural habitats.

After months of private guitar lessons, the band for the movie called “The Flash” came together and rehearsed as a unit for a month, inside a closed bar in New York. The rehearsals not only sharpened Streep’s musical ability, but gave “The Flash” time to bond as an actual group - a unity that translates into the film.

“They were a real band! They had developed great friendships. All the musicians were excited to develop chemistry with Meryl,” Demme says.

The look of Ricki Rendazzo’s character was also Streep’s creation, from the eyeliner and braids to the leather and lace. She worked in tandem with the film’s costume designer to create the look, without even the director knowing where the vision was headed.

Streep has an exceptional talent for understanding characters and knowing how they should be presented, and those who work with her trust her to do what is best.

Diablo Cody, writer of the film (who won an Academy Award in 2007 for her debut screenplay Juno), said the character of Ricki Rendazzo was based on “Stevie Nicks, Joan Jett, maybe a little Melissa Ethridge, and my mother-in-law,” Terry Cieri, who is a mother of six and plays in a band in New Jersey. Cody was intrigued by the “normal” life behind musicians which people generally overlook.

Cody showed Streep some YouTube videos of her mother-in-law, but as she told Vanity Fair, admits the character of Rendazzo was mostly Streep’s vision. “I don’t know if she actually used them for inspiration. She has this really incredible approach to grasping her characters and I think a lot of it is work that she does alone, and I can’t begin to understand how she does it and why she is so great.”

While it’s hard to judge which of Streep’s vast library of memorable characters will stand the test of time as her defining film moments, Ricki is certainly unique in comparison, and another fantastic example of the actor’s aptitude for character creation and conviction.