In 1978, she starred in the musical film Grease, whose soundtrack remains one of the world's best-selling albums of recorded music. With global sales of more than 100 million records, Newton-John is one of the best-selling music artists from the second half of the 20th century to the present. Eleven of her singles (including two Platinum) and 14 of her albums (including two Platinum and four 2× Platinum) have been certified Gold by the Recording Industry Association of America (RIAA). She is a four-time Grammy Award winner whose music career includes five US number-one hits and another ten Top Ten hits on the Billboard Hot 100, and two Billboard 200 number-one albums, If You Love Me, Let Me Know (1974) and Have You Never Been Mellow (1975). Dame Olivia Newton-John AC DBE (born 26 September 1948) is a British-born Australian singer, songwriter, actress, entrepreneur and activist.