"But I didn't know that I would be able to make a career of it. But I'm very grateful that I could," she said during a telephone interview from California where she has lived since the early 1970s.
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Newton-John will perform at 8 p.m. Saturday, Feb. 23, at H. Ric Luhrs Performing Arts Center on the campus of Shippensburg University in Shippensburg, Pa.
"(The audience) should expect singing," she said with a hearty laugh, her familiar Australian accent still prominent. "It's really a little journey in music," she said of the show.
In all, she had 10 No. 1 singles amongst the pop and country charts in the 1970s and '80s, including, "I Honestly Love You," "Have You Ever Been Mellow," "Please Mr. Please" and "Come on Over."
Newton-John was born in England, but moved with her family to Australia at the age of 5. Her career in the United States began in the early 1970s, when she saw success on the country charts, after a manager thought country-folk music suited her voice well. "Thank goodness for (him)," she said.
"Let Me Be There," was her first top 10 single. She was named Most Promising Female Vocalist by the Academy of Country Music and won a Grammy for Best Country Vocalist. In 1974, she was named the Country Music Association's Female Vocalist of the Year, beating out the likes of Loretta Lynn, Dolly Parton and Anne Murray.
All this came before she was propelled to superstardom in 1978 for playing Sandy Olsen opposite John Travolta's Danny Zuko in the mega hit movie version of the musical, "Grease."
Newton-John said before "Grease," she had roles in two other movie musicals. In 1965, her first role was in "Funny Things Happened Down Under," and in 1970, she appeared in "Toomorrow," (sic) a comedy/science fiction/musical. She said neither movie was successful.
"I was really anxious about making ‘Grease,' because I'd already made two bomb musicals. I guess I had a lucky third," she said.
Later, she starred with Gene Kelley in "Xanadu," which spurred soundtrack hits with the title track and "Magic." She had the biggest hit of her career in the early 1980s with the album "Physical," and its title track.
In 1992, Newton-John was diagnosed with breast cancer, and since her recovery remains committed to fundraising and advocating for early diagnosis and a cure for breast cancer.
In June, after raising some $200 million, she opened The Olivia Newton-John Cancer & Wellness Centre in Heidelberg, a suburb of Melbourne, Australia.
"(The process) was arduous and exciting," she said. "I just believed it would happen. I didn't know how it would, and I didn't know how long it would take. But it took 10 years from when we first started fundraising until the doors opened. And this year, the second half of the hospital and the wards open, so it's very exciting."
In 2005, she also opened Gaia Retreat & Spa in Byron Bay, New South Wales, Australia, to promote health and provide a place for healing and relaxation.
"My (spa) is very, very successful," she said. "We've won many, many awards and I'm very proud of that."
In concert, though, she said she performs music from throughout her 40-plus-year career, including her early country hits, soundtrack music and songs from "Gaia," her album of reflection recorded after she battled breast cancer, and a healing CD, "Grace and Gratitude: Renewed," which she released in 2010.
Newton-John said her fanbase and concert audience are "very mixed."
"When I do my shows, there are little kids 9 years old, and their grandparents are with them. So I think it's very interesting for me, that a) they still come, and b) that there's such a wide range of people," at the shows, she said.
During the 2012 holiday season, she and "Grease" co-star and longtime friend John Travolta released an album, "This Christmas." The album contained new music as well as traditional holiday songs. Newton-John said after Travolta presented her with the idea of recording together, she suggested they do it for charity.
"So that was really a reason to do it, there was a cause behind it and a purpose," Newton-John said.
The proceeds from the album are split between Newton-John's cancer and wellness center and the Jett Travolta Foundation, a nonprofit that helps children with special needs, and was named in honor of John Travolta's son, Jett, who died in 2009.
Newton-John also works with her husband John "Amazon John" Easterling, who is owner and founder of Amazon Herb Co. They spread the word about the importance of preserving the rainforest, and help the indigenous people of the Amazon get clean water to gain ownership and title to their land.
How does she balance her performing and activism? "I have a juggling career also," she joked. But added, "It all seems to fall into place for me. I set aside a certain amount of time if I'm going to do singing, and then I work the other things around it."
At 64, though, she said she might cut back on her touring schedule.
"(My priorities are) my work with my hospital and my work with my husband with the Amazon, and my retreat spa," she said. "These things really take priority to me because they are about healing and health and so I kind of work my career around those things now. So that is really kind of my priority, but I still love to perform. But after this year, I probably won't do as much of that."
Olivia Newton-John has been performing for more than 40 years. She will sing hits from throughout her career Saturday, Feb. 23, at H. Ric Luhrs Performing Arts Center at Shippensburg University in Shippensburg, Pa.
If you go ...
WHO: "An Evening with Olivia Newton-John"
WHEN: 8 p.m. Saturday, Feb. 23
WHERE: H. Ric Luhrs Performing Arts Center at Shippensburg University, 1871 Old Main Drive, Shippensburg, Pa.
Cost: Tickets cost $39 to $59
Contact: Call 717-477-7469 or go to luhrscenter.com
More: Olivia Newton-John is online at www.olivianewtonjohn.com and on Twitter @OliviaNJ and Facebook @OliviaNewtonJohn.