By Betsy Sherman

This is a feminist battle where all participants wear marshmallow boxing gloves.

The High Note, directed by Nisha Ganatra. Streaming as of May 29.

Tracee Ellis Ross in The High Note. Photo: Glen Wilson / Focus Features.

The cinematic pairing of a middle-aged female achiever with a younger female assistant and/or protégée has its grand-mama in that juicy 1950 drama about the New York stage, All About Eve. The younger Eve was both a mirror for and threat to the older Margo. These stories don’t always involve sabotage, but usually deliver some sparks, and hint at a mingling of identities and ambitions. Twenty-first century examples include The Devil Wears Prada; the Olivier Assayas-directed Clouds of Sils Maria; and last year’s Late Night, written by and starring Mindy Kaling and directed by Nisha Ganatra.

Late Night had comedy writer Kaling trying to nudge talk show host Emma Thompson toward trusting her own comic instincts and taking creative risks. Ganatra is back on the same turf with The High Note, but this movie, set in the music industry, has too many false notes.

Dakota Johnson plays Maggie, a young woman buoyed by the music of her idols Aretha Franklin, Joni Mitchell, Brian Wilson, Sam Cooke, and — in the movie’s universe — pop star Grace Davis (Tracee Ellis Ross), whose assistant she’s been for three years. During her few hours off from that demanding job, Maggie’s been in a recording studio, honing skills she’ll need for her dream job of music producer.

Laudable jumping-off point: a talented young woman wants to make it in a male-dominated arena. Will she be helped by her high-profile boss/mentor, or will some sort of friction get in the way? With The High Note, there’s no real excitement in taking the leap. The movie is gentle to a fault, with a clumsy screenplay by Flora Greeson. This is a feminist battle where all participants wear marshmallow boxing gloves. There’s warmth in the performances by Johnson and Ross, but Ganatra doesn’t create a believable world for their characters to inhabit.

After a “success” montage proves that Grace is a really-big-deal, we learn that the singer is about to leave the luxury of her Los Angeles mansion to go on tour (via the luxury of her private jet). But Grace hasn’t put out new material in 10 years, only greatest-hits collections. She’s being urged by her old friend and manager Jack (Ice Cube) to accept the offer of a residency at Caesar’s Palace in Las Vegas, where she can recycle the old act indefinitely, and he can enjoy life off the road. However, the always-supportive Maggie wants Grace to challenge herself by writing and recording new songs.

After the tour, Jack hits on yet another way to exploit Grace’s back catalog, an electronic dance remix by a big-name DJ. For Maggie, it’s now or never to reveal the fruits of her long nights in the studio — her own remix of Grace’s work. Never mind that it’s superior to the DJ’s dreck, Jack gives Maggie a verbal smack-down, saying if she ever wants to think about producing, she’d better start from the bottom and develop her own clients.

Which really is as it should be, even though the movie gives the audience a cheap thrill by having Grace tell Jack, “Use hers,” that is, Maggie’s mix — even though there’s no confirmation that her mix is ever used. What’s more, this whole exchange points out the curious absence of any real producer in Grace’s professional circle, as if there were a vacuum that Maggie could just step into.

Anyway, the next phase of Maggie’s story involves David, a young man who flirts with her in a market, which leads to a mutual quizzing over musical tastes. Maggie exits the market to find David singing on the promenade, and he has a knockout voice (is it a thing that they meet over produce and then she wants to pro-duce him?). She convinces David she can, ahem, fit him into her busy schedule of clients. They do in fact make beautiful music together (the movie has some catchy tunes, I’ll give it that). Maggie wants to find a way in which David can perform for Grace; her implausible scheme, and what follows, turn the movie into a five-car collision of contrivances.

Dakota Johnson conveys Maggie’s passion for music and her knowledge of, well, a certain era of it — it’s at the very least an eyebrow-raiser that the girl has no interest in any musical artist younger than her parents. Maggie’s ambition feels real, in a laid-back, fringed suede jacket–wearing Laurel Canyon way (though it made me long for the buzzy energy of Anna Kendrick’s mash-up demon in Pitch Perfect). Johnson’s scenes with Kelvin Harrison Jr. (Waves, Luce) as David are sweet; we never for a second believe the brief lip service given to not mixing business and romance. One of the movie’s highlights is when they write a song together (seriously, nothing beats having characters write a song together for bringing them into sync over a compact period of time — even Ishtar was never faulted for its songwriting scenes).

I wanted to avoid the word diva, but yeah, Grace is our 40-something diva, and Tracee Ellis Ross humanizes the stereotype. The star of the sitcom Black-ish (and narrator of its spin-off, Mixed-ish) is also, famously, the daughter of Diana Ross, so she has seen the species close-up. This is Ross’s first professional music project. No doubt about it, she can sing, and wear shiny gowns with flair, but better than those accomplishments, she brings a mischievous sense of humor to her character.

Ross falls victim to one of the script’s flaws, the shoehorning of exposition into the dialogue — really, does Grace need to tell Maggie she’s won 11 Grammies? But thankfully there are also some wordless ways in which the actress exhibits Grace’s strengths (she takes pleasure in driving sports cars) and vulnerabilities (her succession of skin- and body-tightening activities can be seen as expressing anxiety about aging, or as an investment in her public persona).

Grace, faced with that decision about Las Vegas, drops a sobering statistic on Maggie: only five women over 40 have had number one singles, and only one of them was black. Ain’t it a bitch that the scary age in All About Eve is still the scary age?

All that said, the high bar in The High Note is set by June Diane Raphael (Long Shot) in the small but delicious role of Gail, former personal assistant to Grace, now in parasitic paradise, living in the pool-house and adorning herself with whatever designer goodies Grace has cast off. Her comic touch rings a hundred percent true.

Betsy Sherman has written about movies, old and new, for the Boston Globe, Boston Phoenix, and Improper Bostonian, among others. She holds a degree in archives management from Simmons Graduate School of Library and Information Science. When she grows up, she wants to be Barbara Stanwyck.