In the opening moments of the HBO documentary “Tina,” Tina Turner doesn’t just command the stage as she’s belting out “Ask Me How I Feel” for a giant stadium of fans. With heels stomping and her hair waving, she owns the stage to such a degree that you half expect bank lenders to materialize by the footlights to sign over the deed. Few if any could ever match Turner as a performer. Both regal and raw, she was one of the supreme vocalists of the 20th century – a model of inspiration for Mick Jagger and countless others. And, at least in scenes like that 1980s concert, her power was a testament of reclamation. As a newly solo singer removed from more than a decade of abuse, she was taking back her life, her story, her voice. Her proper debut, she says, came not as a teenager with Ike Turner, but as a 50-year-old woman finally on her own. The story has rightly taken on the shine of legend. The remarkable arc of Turner’s life has already been the stuff of a best-selling autobiography (1986’s “I, Tina”), a Hollywood biopic (1993’s “What’s Love Got to Do With It”) and a Broadway show (“Tina: The Tina Turner Musical”). So why more? Well, partly because music documentaries have proliferated during the streaming era. Everyone from Billie Eilish to Linda Ronstadt has recently gotten in on the act. But there’s a better reason for “Tina,” Dan Lindsay and T. J. Martin’s new documentary, premiering Saturday on HBO and HBO Max. The film, as you would expect, walks us again through the tremendous upheavals in Turner’s life. But it’s ultimately about Turner telling her story – why she struggles having to tell it; why she needs to tell it, anyway; and why she wants to be done with it. Turner may be the protagonist of a drama with great swings between oppression and liberation, but it’s not a role she has any natural affinity for. “I just really don´t want to play the part,” she says in an earlier interview heard in “Tina,” referencing the 1993 movie. “It was just so unlike me, my life.” That gives “Tina” an unusual tension. In a way, Turner rejects her own biography. Not the facts of it, but the emphasis on certain chapters. The 81-year-old Turner, who gave her support to the documentary, appears in modern-day interviews from Switzerland where she seems content to put much of it to bed. This, we’re meant to gather, may be her final word on her life story. With archival footage and interviews, “Tina” first plunges back to her years in the Ike & Tina Turner Revue. The contrast between their stage presence and private life is drastic. Before crowds and cameras, they’re a sensational, exuberant rock and R&B duo; behind closed doors, he’s an abusive, controlling monster. Turner, then Annie Mae Bullock, was 17 when she met Ike, a rock `n´ roll pioneer. In their television appearances, he seems the quiet, supportive sideman. Few beside Turner knew that off-stage he was a thin-skinned tyrant. It’s especially telling that next to Ike, Phil Spector comes off like a more sensitive collaborator when they record 1966’s “River Deep – Mountain High” with him. (It’s one of the disappointingly few but always rewarding times the filmmakers pause to linger on a recording session.)