Olivia Newton-John recalls the making of the cult favorite

By Missy Schwartz
Updated July 22, 2010 at 04:00 AM EDT

John Travolta was 23 years old and had just been cast as Danny in the film adaptation of the popular stage musical Grease when he told his producers whom they should hire as Sandy. But Olivia Newton-John, a successful recording artist with limited acting experience, was unsure about playing a high school student. ?I was 29 and worried that I didn?t look young enough,? she says. Then Travolta visited her at her home, and there went her reservations. ?John and I had great chemistry from the first time we met,? she says. ?We?re bonded forever on celluloid.?

Grease, the raunchy-sweet 1950s-set musical, remains one of the most beloved movies of all time. Released in June 1978, it grossed $160 million and spawned a chart-topping soundtrack of enduring tunes. Singing, dancing, and swooning teens—it may be the perfect summer movie. ?I don?t think we ever imagined it would become so popular and go for so long,? says Newton-John, 61, who recently guest-starred on Glee and will appear in a cancer-awareness documentary, 1 a Minute, this fall. ?But every seven years or so, a new group of kids finds the movie.? And starting July 8 in 13 markets (and more if enough people request it via the online service Demand it!), Paramount is releasing Grease: Sing-A-Long, a studio-sanctioned version of the audience-participation screenings that fans have been organizing for years. Didi Conn, who played Sandy?s pal Frenchy, will host the premiere at the Hollywood Bowl on June 25.p>

Where Are They Now?
Here?s what some of the Grease stars have been up to since graduating from Rydell High.

Didi Conn (Frenchy)
After returning for 1982?s Grease 2, Conn, 58, starred on TV?s Benson. She?s currently developing an animated kids? TV show. The mother of an autistic son, she?s a spokes-person for Autism Speaks.

Stockard Channing (Rizzo)
Renowned for her Emmy-winning work on The West Wing, Channing, 66, also scored an Oscar nom for 1993?s Six Degrees of Separation and a Tony for 1985?s A Day in the Death of Joe Egg. She was recently in the indie Multiple Sarcasms and is still active on the New York stage.

Jeff Conaway (Kenickie)
Conaway costarred on TV?s Taxi and Babylon 5. In 2008, the actor, 59, went public with his substance-abuse problems on Celebrity Rehab With Dr. Drew.

Sid Caesar (Coach Calhoun)
The influential comic, 87, appeared in Grease 2 and in 1997 earned his 11th Emmy nom for guest-starring on Mad About You. He lives in California.

Annette Cardona (Cha Cha)
The Pink Ladies? nemesis (then Annette Charles) popped up on The Incredible Hulk and Magnum, P.I. before retiring. Now 62, she?s a speech professor in California.