Angel Olsen grew up in St. Louis, the youngest daughter in a family of nine. She was adopted, at 3, by the much older couple who had been her foster parents since soon after her birth; when she was a child, her oldest siblings were already adults, living elsewhere. She felt as if she belonged in the family, but she also noticed the age difference. Her friends frequently mistook her parents for her grandparents. Even at an early age, she was fascinated with the music of the 1930s, the sound of her parents’ youth. “I wanted to relate to them and understand what they did when they were young,” she says. “So I would go into my parents’ room and take out all the photo albums and put the photos out on the bed and kind of look up music from that time and obsess over that time period and try to understand what their childhood was like.”

Her family was old-fashioned and religious, her mother loving and her father reserved; they were poor, but Olsen had piano and guitar lessons, and on birthdays her mother would take her to the St. Louis Symphony to hear classical music. In high school, she began to have intermittent pneumonia and severe weight fluctuations — she went from being at the base of the cheerleading squad’s pyramid formation to being the one they wanted to throw in the air — before finding out she had a thyroid disorder. Around the same time, her mother became sick, her grandmother became sick and a close friend began showing symptoms of schizophrenia. “I watched them going from being really there to not being hardly there at all,” she says. “And still having a body, walking around, doing things.” It’s been a theme in her life, she says, watching people stay alive but suffer through it.

It was only later that Olsen began to appreciate how lucky she’d been as the youngest in the family, growing up with the sort of independence more often associated with being an only child. She became driven, self-sufficient and, she says, used to getting her way. She would sing songs into a Panasonic tape recorder, playing them back over and over again to hear what she could do differently, mapping the reaches of her voice and learning to sculpt its nuances. “I became very obsessed with recording,” she says, as “a tool to remember how things sounded but also how they felt when they sounded that way” — the audio equivalent of practicing expressions in the mirror until you can effortlessly summon the perfect smile or glare. Later, after she moved to Chicago and began making music — including touring as part of the backing band for the influential Bonnie Prince Billy — she brought bits of that education to bear, letting her voice slip neatly into a half-yodel or an elegant Elvis sneer or singing in a plaintive folk style that wouldn’t feel out of place on a Karen Dalton album.

In one sense, these stylistic nods to the past made her part of a lineage shared with musicians like Roy Orbison and Patsy Cline — artists whose work helped define American popular song as a temple to strong emotions nonchalantly expressed. (Olsen has certainly had her singing compared to Roy Orbison’s far more than any other young woman of the 21st century.) But those throwback influences could also be seen as a way of anchoring her songwriting in a more private space — a way of blocking out some of the noise of the present so she could hear her own voice more clearly. Something similar is true of the minimal instrumentation on her earliest work, which often features Olsen’s voice and electric guitar alone — a choice guided by her desire to convey an emotional message rather than making a purely beautiful song. If every human voice begins as a means of pure expression rather than rational utterance, Olsen knows something about how to return that expressivity to her words, bending and sculpting the lines until they start to feel primal again.

It’s that protean plasticity, combining pieces of many different eras, that marks Olsen’s vocal style. She can sing loud, big and pretty, but often prefers not to. Instead, as she moves in and out of folky tremolos and full-throated rock yowls, she pushes her writing to the foreground. On her 2014 breakthrough, “Burn Your Fire for No Witness” — the music website Pitchfork ranked it the 15th-best record of the year — she was often fragile or doleful or tender, singing lines like “Won’t you open a window sometime/What’s so wrong with the light?” Two years later, the catchy single “Shut Up Kiss Me,” from a rock-’n’-roll-heavy album called “My Woman,” had her cycling through an array of ’60s attitudes, swerving from breathy songstress to rockabilly bombast within single lines, trying on campy Orbison drama one second and a Joplin staccato the next. Behind the tour of vocal stylings, you sensed Olsen winking at the contradictory tropes of pop love songs while simultaneously asserting her presence as a woman — one who could deploy every trick in the rock handbook with a knowing, feminine bravado all her own.