'Grease' celebrates its 40th anniversary Fans are hopelessly devoted to the John Travolta and Olivia Newton-John classic.

Forty years later, fans are still hopelessly devoted to "Grease."

The iconic musical starring Olivia Newton-John and John Travolta celebrates its 40th anniversary on June 16.

At the time of its release in 1978, "Grease" became the highest-grossing musical ever, breaking the 13-year record held by "The Sound of Music." It's currently the second-highest grossing live action musical, after the 2017 version of "Beauty and the Beast."

The soundtrack of the movie was also hugely successful, and featured the hit title theme, sung by Frankie Valli, as well as "You're the One that I Want," the Oscar-nominated "Hopelessly Devoted to You" and "Summer Nights."

Earlier this year, in honor of the anniversary, "Grease" came back to the big screen for two nights only as part of the Turner Classic Movies Big Screen Classics series. It also received a special 40th anniversary edition Blu-ray and DVD release, which came out on April 24.

The story and songs of Grease continue to attract generations of fans: In 2016, Fox aired a live remake of the musical starring Julianne Hough which attracted great ratings. Travolta appeared on ABC's "Good Morning America" this week and discussed the film's long-lasting appeal.

"It's like any great piece of art or work: It's interpretive," he said. "So actually, it would be a question that individuals would answer better than I could."

"I just know I love it and have always loved it," he added. "I did it on Broadway, I did it on the road -- my daydream was to do it in the movies."