Madonna couldn’t do it. Neither could Justin Timberlake or Britney Spears. And so far, neither have (apologies to their many, many fans) Harry Styles, Beyoncé or Taylor Swift.

With “Wicked: For Good,” Ariana Grande did the near-impossible. She proved that the first film was no fluke — and that she has definitively made the perilous crossover from pop icon to movie star.

Grande, who got her start as a performer on a Nickelodeon sitcom and who delights every time she shows up on “Saturday Night Live,” is no stranger to acting. But there’s acting, and then there is star power. As Glinda Upland, Grande does more than hold her own opposite Cynthia Erivo, who entered the franchise already a Tony winner and, for “Harriet,” a past Oscar nominee. She carries across a lifetime of yearning in a way that transforms Glinda from would-be witch in a surreal landscape into a young woman to whom anyone can relate.

Erivo is, too, fantastic in “Wicked: For Good,” but her talents as an actress were better-known before these films came out, and the second installment is far less her film. Grande may be getting a push in the supporting races this awards season, but it’s her journey — from glum acceptance of her role as a figurehead in the corrupt world of Oz to eager, revived defiance — that gives the tale its structure and its heat.

The fact that pop-star-to-screen-star is a career transition so rarely nailed makes a certain kind of sense: Recording artists accustomed to arena crowds there solely to see them as the one star onstage can tend to pick projects that will be easy for them to nail, and that lack a certain quality of risk. (Little wonder that Madonna’s one unambiguous movie triumph was “Evita,” for which she had to retrain her voice, or that Cher won an Oscar only once she stripped off all her glam and transformed into an outer-borough bookkeeper.) And, once in those roles, pop stars can tend to coast on easy, inborn charisma rather than building out a character. (Justin Timberlake nailed shallow and callow in “The Social Network,” but further roles suggest that may be the only note, as an actor, that he can hit.)

Glinda is a vocally challenging role with a massive emotional arc, and one that is iconically associated with a beloved star. Nailing Glinda’s journey from snob to rebel — and achieving escape velocity from the gravitational pull of Kristin Chenoweth — would be a massive challenge, so much so that Grande has discussed the challenge of even convincing Team “Wicked” to see her. They needed an actress, the thinking went, not a pop star.

Surprise! They got the former. Grande holds the screen and, with Erivo, has catalyzed a million memes over two press tours. But — give or take the next “Meet the Parents” sequel — material as strong, or as pre-sold, as “Wicked” is rare. The idea that Grande might someday play Audrey Hepburn is bandied about online frequently, and she’ll certainly act again, but this newly minted actress’ next moves will prove whether it’s her that is bankable or simply the “Wicked” IP. They’ll also indicate whether Hollywood still knows what to do with a charismatic emerging star whose ambition is, for once, as grand as her talent.

Say this much: Grande is committed. Her recent comments that her forthcoming music tour will represent a “last hurrah” make clear just how much she has given of herself to the performance of Glinda — a shedding of any pop-star vanity she may have had in order to build a Glinda who worked onscreen, and at a political moment the film could be read as addressing. In her new solo song, “The Girl in the Bubble,” written for this film, Grande sings about Glinda herself, and how it is time for her to put her delusions and her sense of herself as a star away in order to be a part of a greater movement. She appears nothing like the singer behind “God Is a Woman” or “Yes, And?” — she allows a tremulous hitch into her voice, and presents a quavering, delicate expression that she might never allow herself to express on a concert stage. “It’s time for her bubble to pop,” she sings — in other words, for Glinda to let go of the gilded world she’s known in order to embrace the risk and danger of the wider world beyond. One imagines that Grande, on the precipice of what may become a major movie-star career, knew what Glinda meant.