Olivia Newton-John, who sang among the largest hits of the 1970s and ’80s whereas recasting her picture because the virginal lady subsequent door right into a spandex-clad vixen — a metamorphosis mirrored in miniature by her starring function in “Grease,” one of the vital in style film musicals of its period — died on Monday at her ranch in Southern California. She was 73.

The loss of life was introduced by her husband, John Easterling. She had lived with a breast most cancers analysis since 1992 and in 2017 introduced that the most cancers had returned and unfold. For years she was a distinguished advocate for most cancers analysis and had began a basis in her title to help it.

Ms. Newton-John amassed No. 1 hits, chart-topping albums and 4 data that offered greater than two million copies every. Greater than the rest, she was likable, even beloved.

Within the earlier section of her profession, this English-Australian singer beguiled listeners with a excessive, supple, vibrato-warmed voice that paired amiably with the sort of swooning middle-of-the-road pop that, within the mid-1970s, usually handed for nation music.

Her efficiency on the charts made that blurring clear. She scored seven Prime 10 hits on Billboard’s Nation chart, two of which grew to become back-to-back total No. 1 hits in 1974 and ’75. First got here “I Truthfully Love You,” an earnest declaration co-written by Peter Allen and Jeff Barry, adopted by “Have You By no means Been Mellow,” a feather of a music written by the producer of lots of her largest albums, John Farrar.

“I Truthfully Love You” additionally received two of the singer’s 4 Grammys, for report of the yr and greatest feminine pop vocal efficiency.

The mixture of Ms. Newton-John’s constantly benign music — she was by no means a favourite of critics — and shapely however squeaky-clean picture triggered many writers to check her to earlier blond ingénues like Doris Day and Sandra Dee. “Harmless, I’m not,” Ms. Newton-John instructed Rolling Stone in 1978. “Individuals nonetheless appear to see me because the lady subsequent door. Doris Day had 4 husbands,” she stated, but she was nonetheless seen as “the virgin.”

An entry into motion pictures in 1978 aimed to place the singer’s chaste picture behind her, beginning with “Grease.” Her character, Sandy, reworked from a pigtailed sq. smitten with John Travolta’s bad-boy Danny to a gum-smacking unhealthy lady. “Grease” grew to become one of many highest grossing film musicals ever, besting even “The Sound of Music.” Its soundtrack was the second best-selling album of the yr, crushed solely by the soundtrack for “Saturday Evening Fever,” which additionally starred Mr. Travolta.

The “Grease” soundtrack spawned two No. 1 hits, each sung by the co-stars, together with the manically lusty “You’re the One That I Need” and the doo-wop romp “Summer season Nights.” A ballad Ms. Newton-John sang alone, “Hopelessly Dedicated to You,” earned the movie’s lone Oscar nomination, for greatest music.

Making use of the evolution of her “Grease” character to her singing profession, Ms. Newton-John titled her subsequent album “Completely Sizzling,” and introduced herself on the quilt in shoulder-to-toe leather-based. The album, launched on the finish of 1978, went platinum, yielding the rock-oriented “A Little Extra Love” with the road, “The place did my innocence go?”

The album featured Ms. Newton-John singing in a considerably extra forceful voice. Although her gross sales dipped because the 1970s become the ’80s, by early within the decade she started essentially the most commercially potent interval in her profession, peaking with the one “Bodily,” which spent 10 weeks on Billboard’s prime perch. Later, the journal declared it to be the largest music of the 1980s.

Olivia Newton-John was born on Sept. 26, 1948, in Cambridge, England, the youngest of three youngsters of Brinley and Irene (Born) Newton-John. Her mom was the daughter of the Nobel Prize-winning physicist Max Born. Her Welsh-born father had been an MI5 intelligence officer throughout World Battle II and afterward served as headmaster at Cambridgeshire Excessive Faculty for Boys.

When Ms. Newton-John was 6, her household immigrated to Melbourne, Australia, the place her father labored as a university professor and administrator. At 14, she shaped her first group, Sol 4, with three women from faculty. Her magnificence and confidence quickly earned her solo performances on native radio and TV exhibits below the title “Pretty Livvy.” On “The Go!! Present” she met the singer Pat Carroll, with whom she would kind a duet, in addition to her eventual producer, Mr. Farrar, who later married Ms. Carroll.

Ms. Newton-John received a neighborhood TV expertise contest whose prize was a visit to Britain. Whereas tarrying there, she recorded her first single, “’Til You Say You’ll Be Mine,” which Decca Information launched in 1966.

After Ms. Carroll moved to London, she and Ms. Newton-John shaped the duet Pat and Olivia, which toured Europe. When Ms. Carroll’s visa expired, forcing her to return to Australia, Ms. Newton-John stayed in London to work solo.

In 1970, she was requested to hitch a crudely manufactured group named Toomorrow, shaped by the American producer Don Kirshner in an try to repeat his earlier success with the Monkees. Following his grand design, the group starred in a science-fiction movie written for them and recorded its soundtrack. Each tasks tanked.

“It was horrible, and I used to be horrible in it,” she later instructed The New York Instances.

Her debut solo album, “If Not for You,” was launched in 1971, its title monitor a canopy of a Bob Dylan music.

After some duds in america, Ms. Newton-John launched the album “Let Me Be There” (1973), which led to a Grammy win for greatest feminine nation vocal efficiency.

Two key adjustments in pop music boosted her profession that decade: the rise of “smooth rock” in response to the tougher genres of the late 1960s, and the mainstreaming — some would say the neutering — of nation music, additionally epitomized by stars like John Denver and Anne Murray.

The latter pattern grew to become a difficulty in 1974, after Ms. Newton-John was chosen feminine vocalist of the yr by the Nation Music Affiliation over extra conventional stars like Loretta Lynn and Dolly Parton. Protests led to the formation of the fleeting Affiliation of Nation Entertainers. But, after Ms. Newton-John recorded her “Don’t Cease Believin’,” album in Nashville in 1976, the friction eased.

The second section of her profession, which started with “Grease,” discovered additional success by a duet with Andy Gibb, “I Can’t Assist It,” adopted by an try to increase her performing profession with the 1980 musical movie “Xanadu,” with Gene Kelly. Whereas the film floundered, its soundtrack went double-platinum, boasting hits like “Magic” (which commanded Billboard’s No. 1 spot for 4 weeks) and the title music, recorded with the Electrical Gentle Orchestra.

A campy Broadway present based mostly on the movie opened in 2007 to some success.

Ms. Newton-John’s smash “Bodily” additionally yielded the primary video album to hit the market, with clips for all of the album’s tracks. “Olivia Bodily” received the Grammy in 1982 for video of the yr.

She was paired once more with Mr. Travolta within the 1983 film “Two of a Type,” an try to repeat the success of “Grease.” However the movie upset whilst its soundtrack proved in style, particularly the music “Twist of Destiny.”

Ms. Newton-John was named an officer of the Order of the British Empire in 1979.

By the mid-’80s, her profession had cooled. For a number of years she in the reduction of on work to take care of her daughter, Chloe Rose, whom she had along with her husband on the time, the actor Matt Lattanzi. That they had met on the set of “Xanadu” and married in 1984; they divorced in 1995. She married Mr. Easterling, the founding father of the Amazon Herb Firm, in 2008

Along with her husband, she is survived by her daughter, Chloe Rose Lattanzi; her sister, Sarah Newton-John; and her brother, Toby.

After studying she had breast most cancers in 1992, Ms. Newton-John grew to become an ardent advocate for analysis into the illness. Her Olivia Newton-John Basis Fund is devoted to researching plant-based remedies for most cancers. Regardless of her personal remedies, she continued to launch albums and tour however didn’t make headway on the charts. She additionally acted in motion pictures and on tv.

In Could 2017, she disclosed that her most cancers had returned and that it had metastasized to her decrease again. She printed a memoir, “Don’t Cease Believin,’” in 2018.

To the top Ms. Newton-John firmly believed in her audience-friendly strategy to music. “It annoys me when folks suppose as a result of it’s industrial, it’s unhealthy,” she instructed Rolling Stone. “It’s fully reverse. If folks prefer it, that’s what it’s imagined to be.”