From "If Not for You" to "Physical," from Grease to Xanadu, from her successful battle against breast cancer to her support of numerous environmental causes, Olivia Newton-John has had a long, fruitful, and impressive career, as Live at the Sydney Opera House, a good-looking, great-sounding, beautifully performed concert recorded in 2006, will testify. Born in 1948, Newton-John is one of those singers who these days would be known as a diva, were it not for the fact that her musical style and overall manner are too self-effacing for so presumptuous a term. And while her voice is a bit less pristine these days than when she came on the scene with a series of country-flavored singles in the '70s, what little she's lost in purity is balanced by an increase in soul; she'll never be Etta James, but once she warms up, she hits the high notes with ease and sings with considerable power and confidence. What's more, though she's usually categorized as an adult contemporary artist, in the course of this career-spanning, 27-song set (backed by a first-rate band and the full Sydney Symphony Orchestra), she reveals herself to be at ease with a variety of styles, ranging from the aforementioned country ("Let Me Be There," "Please Mr. Please," and a rousing version of Dolly Parton's "Jolene") through soft pop ("I Honestly Love You," "Have You Never Been Mellow"), the movie hits (two from Xanadu and three from Grease), an electronically re-created duet with the late Peter Allen ("Tenterfield Saddler"), and even a creditable go at the torch standard "Cry Me a River." There are no DVD bonus features, but between-songs bits find Newton-John, daughter Chloe Lattanzi, and members of the band providing a tourist's eye view of Sydney. --Sam Graham