In 1978, Grease was the word. And Olivia Newton-John proved she could be America's darling as both the sweet, sweater-clad character seen throughout most of the movie -- and the black-leather bad girl glimpsed at the end. Starring with a young, lean John Travolta in the cinematic romp that's still the top movie musical ever, Newton-John attained superstar status after being sewn into impossibly tight pants for Grease's final scene. The film's phenomenal popularity surpassed all her prior success -- namely, 1971's hit cover of Bob Dylan's "If Not for You." Chart-busting soundtrack singles helped Australia's songbird become pop's queen, especially impressive when her music's enduring power is compared to contemporaries like Diana Ross (but try finding a twelve-year-old girl who knows any of Ms. Ross's numbers). Syrupy ballads sometimes grate after puberty's passed or heartbreak's over, but ONJ's up-tempo classics are impossible to forget and make for some good "guilty pleasures." While Xanadu tanked at the box office (despite Gene Kelly's help), its title track was a roller-disco favorite, now pure nostalgic gold. And even the most lethargic listener must tap a toe to the irresistible hook in "Physical." With vocals that swoop from wholesome to seductive to soulful, Newton-John's albums are always interesting. While her addictive melodies and ultra-catchy rhythms netted her a star on the Hollywood Walk of Fame, the several Humanitarian Awards earned by this breast-cancer survivor and activist far outshine her musical accomplishments. You have to believe we are magic when Newton-John performs at Colorado's State Fair this Wednesday, September 1 and at Universal Lending Pavilion on Thursday, September 2.