Helen Reddy, the Australian singer behind feminist anthem I Am Woman, has died aged 78.
Reddy died on Tuesday in Los Angeles, her family said in a statement on Facebook.
Her children Traci Donat and Jordan Sommers described her as a "wonderful mother, grandmother, and a truly formidable woman".
"Our hearts are broken. But we take comfort in the knowledge that her voice will live on forever."
Reddy, who had Addison's disease and was diagnosed with dementia in 2015, spent the last years of her life in a celebrity care home in Los Angeles.
She had a string of pop-rock hits in the 1970s, but is best known for the 1972 anthem I Am Woman - which became prominent in the women's liberation movement.
A sleeper hit, it went on to sell millions of copies worldwide, making Reddy the biggest-selling female artist globally for two years running.
In collecting her 1973 Grammy Award for best female vocalist, Reddy famously thanked "God because she makes everything possible".
Born in Melbourne in 1941, Reddy grew up in a showbiz family with actor parents, and performed regularly as a child.
After winning a talent contest in Australia, her prize ticket took her to New York City in the 1960s, where she auditioned for a recording contract.
That opportunity fell through but the soprano decided to stay on in the US, later signing with Capitol Records.
Her first hit, I Don't Know How to Love Him, was followed by a succession of others including Crazy Love, Delta Dawn, and Angie Baby.
But it was her second hit, I Am Woman, which catapulted her to international fame and became a defining song for a generation of women.
Reddy said she had penned the lyrics - with lines such as "I am woman, hear me roar" and "I am strong, I am invincible, I am woman" - after struggling to find other songs which reflected her pride in being a woman.
Singer 'paved the way'
Among those to pay tribute on Wednesday was Unjoo Moon, who directed a biopic about Reddy - titled I Am Woman - which was released earlier this year.
"She paved the way for so many and the lyrics that she wrote for I Am Woman changed my life forever like they have done for so many other people and will continue to do for generations to come," Moon said.
Actress Jamie Lee Curtis shared a clip of Reddy singing her anthem at a Women's March protest in Los Angeles in 2017, part of global rallies which directed anger at US President Donald Trump.
"Honor of my life. Introducing Helen at the Women's March," she wrote, adding: "Read the lyrics".
Fellow actresses Jane Lynch and Patricia Arquette and 1970s singing group The Pointer Sisters also posted tributes.
At the height of her fame, Reddy toured internationally and was a regular guest on Hollywood showcase shows.
She hosted a season of the Helen Reddy Show on NBC TV in 1973, and a year later was awarded a star on the Hollywood Walk of Fame.
Later in her career she also featured in a handful of films and stage musicals.