It’s the spring of 1975, and you’re a dyed-in-the-wool fan of the propulsive soul and R&B music that percolates out of your AM transistor radio with reassuring regularity. You’re enthralled by such earth-shaking nuggets as The Isley Brothers’ blistering “Fight the Power,” Ohio Players’ molten “Fire” and Labelle’s sizzling “Lady Marmalade.”

Easing between these titanic sonic blasts is something that begins with chirping birds, gently arpeggiating acoustic guitar and the rippling tones of a Fender Rhodes electric piano. An impossibly pure and pleading soprano voice coos, “Loving you is easy ’cause you’re beautiful.” This sonic reverie reaches its apex with the quintessential money note—a jaw-droppingly high “oooooh” that would foreshadow both Mariah Carey and Ariana Grande’s stratospheric vocal feats.

Whether because of or in spite of its marked contrast to the thundering jams cited above, “Lovin’ You” became a #1 R&B hit in April 1975 as funk was peaking and disco was about to explode.

By then, the singer and co-writer of this song, Minnie Riperton, was already a seasoned veteran of the Chicago music scene, having made her bones in the ’60s, first as a session singer and girl-group member and then as an integral part of the multiracial, mixed-gender psych-soul ensemble Rotary Connection.

Blessed with a four-octave vocal range and encouraged by the band’s maverick producer-arranger, the great Charles Stepney, Riperton thereafter embarked on a solo career that deftly eschewed the formulaic and histrionic to focus on her buttery soprano and the romance of her writingâ€•husband Richard Rudolph was a frequent collaboratorâ€•to convey an earthy soulfulness not unlike that of Stevie Wonder, who would become her producer.

By the time of her untimely death in 1979, Minnie Riperton had generated a substantial body of work that would be rediscovered and treasured in the decades that followed by crate-digging hip-hop auteurs, music supervisors and other obsessives.

She was born in Chicago in 1947 and raised in an arts-oriented household. Her family, recognizing the uniqueness of her unusual coloratura soprano—which spans the astounding “whistle register,” the absolute highest of the soprano range—nurtured her gifts. Minnie immersed herself in opera and show tunes, developing breathing techniques to extend her already-formidable vocal range.

A voice like Riperton’s would surely have been prized in the opera world, but the fertile musical climate of 1960s Chicago, where blues, rock, jazz and R&B reigned supreme, won the battle for Riperton’s musical soul.

At 15 she joined The Gems, an all-female act that put out a few releases but mainly served as backup singers for artists like Song Three and The Starlets. It was through this experience that Riperton met Billy Davis, the Chess Records A&R director who’d helped shape the sounds of Etta James and Jackie Wilson. Acting as an early mentor to Riperton, Davis released her first solo single, the dramatic “Lonely Girl,” under the moniker Andrea Davis.

In 1967, immersing herself in the heady environment at Chess (where she briefly served as a receptionist) and already garnering respect for her distinctive voice, Riperton was tapped to join Rotary Connection. The brainchild of Marshall Chess (son of label founder and President Leonard Chess) and local vibraphonist-producer-arranger Stepney, Rotary boasted a rotating cast of what Chess hailed as “the hottest, most avant-garde rock guys in Chicago.”

With Minnie as co-lead singer, the band recorded six albums between 1967 and 1971, each filled with imaginative originals and radically reworked covers of hits like Otis Redding’s “Respect” (reimagined as a distortion-drenched acid-soul opus); The Lovin’ Spoonful’s “Didn’t Want to Have to Do It” (enhanced with reverb, massed vocal layers and other psychedelic effects); and The Band’s “The Weight,” Rotary Connection’s funky, string-laden version of which could’ve been at home in Hair or Godspell.

Riperton’s otherworldly soprano boosted the power and gravitas of the band and, on such selections as their rendition of Jimi Hendrix’s “Burning of the Midnight Lamp,” lent it a neo-classical grandeur. While Rotary didn’t score big sales or radio hits, it earned a loyal following and opened for the likes of Led Zeppelin, The Rolling Stones and Janis Joplin.

The band’s recorded peak undoubtedly came in 1971 when, as The New Rotary Connection, it released the masterful “I Am the Black Gold of the Sun,” a spellbinding amalgam of jazzy stacked vocal harmonies, relentless groove and fuzz-soaked guitar.

All of Rotary Connection’s releases were produced and arranged by Stepney, who by all rights should be spoken of in the same reverential tones reserved for such brilliant record makers as Quincy Jones, Motown’s Norman Whitfield and legendary “fifth Beatle” George Martin. Stepney would also produce material by Muddy Waters, Howlin’ Wolf, Ramsey Lewis and Earth, Wind & Fire. His masterful arrangements, coupled with a fearless enthusiasm for the psychedelic rock of the day—an affinity not shared by many of his jazz-purist contemporaries—brought a distinctly cinematic sensibility to his body of work, which has subsequently found favor with hip-hop, R&B and EDM artists.

Stepney’s career was cut short by a fatal heart attack in 1976, when he was just 45 years old.

In 1969, while still in Rotary Connection, Riperton recorded her debut album, Come in My Garden, with Stepney for GRT Records. Released in 1970â€•it was reissued on the Janus label as “Lovin’ You” began ascending the charts four years laterâ€•the record opens with a true career highlight, the chamber-soul masterpiece “Les Fleurs,” a trippy pastoral sung from a flower’s point of view that blossoms into an anthemic chorus.

Though the album is now widely regarded as something of a landmark of psychedelic soul, it was a commercial disappointment upon release. Riperton abruptly retreated from the music business, leaving behind both Rotary Connection and her budding solo career to begin raising a family in Gainesville, Fla. (Riperton and Rudolph’s son, Marc Rudolph, is a prominent recording engineer; daughter Maya Rudolph became a household name on Saturday Night Live). In an installment of the Riperton documentary series Unsung, Richard Rudolph described their Florida refuge as “a magical, enchanted bubble in the middle of redneck country.”

The singer’s story may well have ended here, but fate intervened; she’d been living a quiet life as a homemaker when a college intern for Epic Records who’d been stunned by a Rotary show, tracked her down. After hearing Richard and Minnie play several songs they’d written, he became their champion. A&R higher-ups heard their demos, duly signed Minnie and convinced the family to move to Los Angeles.

This time around, Riperton delivered a gold mine of breezy, acoustic-tinged ballads as well as funky, wah-wah-imbued numbers, all replete with spine-tingling “whistle register” moments. She approached none other than Stevie Wonder to helm the project (with Rudolph’s vital assistance). He was utterly captivated by Minnie’s voice, dubbing it “the eighth wonder of the world.”

“The idea was to try to keep it organic and let people get close to Minnie,” Rudolph said of the approach to the recording during an interview with okayplayer. “Of course, what I would try to do was stay out of Stevie’s way. That guy was a force of nature. He and Minnie were so close and loved each other so much. It was such a beautiful thing to see them together and to see them writing and working together and singing together… We never had a bad moment.”

Since Wonder was under exclusive contract to Motown, he adopted the moniker “El Toro Negro”â€•“Black Bull”â€•though his famously distinctive harmonica was unmistakable. The resulting album, 1974’s Perfect Angel, ranks as one of the eclectic gems of early ’70s soul, with the producer’s sonic and compositional imprint also heard distinctly on ballads like “Seeing You This Way” and “The Edge of a Dream.”

But make no mistake: “Lovin’ You” is 100% Minnie Riperton. Written to soothe infant daughter Maya’s restlessness so Minnie and her husband could enjoy some private time together, the song nestled Minnie’s incomparable voice atop a delicate bed of acoustic guitar (played by Rudolph) and Rhodes (played by Wonder).

Though the initial version was sublime in its simplicity, Riperton felt there was something missing. “We went back and listened to the demo [recorded at] our place in Gainesville,” Rudolph recalled. “The window had been open and there was a bird singing outside. Stevie said, ‘Get the bird.’ We went out to the UCLA Botanical Garden with his Nagra tape recorder, and Minnie would sit there and try to sing these really high bird calls and get birds to sing.”

Graced by the requisite chirping, the tune rose to #1 on the Pop chart and went gold. The notoriety Riperton achieved led to splashy TV appearances on The Tonight Show, The Midnight Special and Mike Douglas, to name a few, where she effortlessly demonstrated that those dazzling high notes were no studio effect. “She loved that spotlight,” said Rotary co-lead singer Sidney Barnes in the Unsung doc, “and the spotlight loved her.”

Riperton released three more albums, Adventures in Paradise (1975), Stay in Love (1977) and Minnie (1979), all featuring intimate showcases of that one-in-a-million soprano. Then, in 1976, she was diagnosed with breast cancer, after which she underwent a mastectomy. The procedure didn’t improve her prognosis, however, and she was given only months to live.

She threw herself into both her music and her newfound role as an advocate for cancer research and treatment. Her public stance was vitally important to helping destigmatize a disease that had too often been ringed by shame. Riperton became the American Cancer Society’s national spokeswoman and was presented with the organization’s Courage Award by President Jimmy Carter, who hailed her for “her frank approach to a problem in her own life and for the inspiration that she has provided for others who might have to face this prospect in the future.”

At this point she was exhausted and unable to move her right arm. She nonetheless defied her life-expectancy odds by a couple of precious years. During that time she remained laser-focused on the things that mattered most—her family, the beauty of nature and the power of song.

Minnie Riperton died on July 12, 1979, in Los Angeles at 31. Love Lives Forever, her final album, was released in 1980.

Shortly after her death, Stevie Wonder performed a musical tribute to Riperton on Soul Train. Before playing a medley of her songs he offered some observations about his friend. “For as long as she lived,” he said, “she lived.”

Riperton’s recorded work continues to inspire fans of both psychedelic soul and romantic R&B, and appreciation for her repertoire now extends well beyond “Lovin’ You,” with “Les Fleurs” in particular reaching a new audience; the magical song has made its way into such high-profile projects as Jordan Peele’s Us and the Watergate-themed Julia Roberts vehicle Gaslit.

And more than three decades after her death, Minnie’s “whistle register” is still a thrillingly singular sound. Despite its ethereality, though, she is remembered as a flesh-and-blood woman whose enduring artistry was the flowering of a deep, adventurous and resilient spirit.