DOLLY PARTON gives ET a sneak peek at the world premiere of the stage version of her 1980 hit movie, 'Nine to Five," which will debut at the Ahmanson Theater in Los Angeles this fall

"This little thing started 27 years ago and it became so popular on TV and everywhere you looked," the "Backwoods Barbie" singer tells ET's special correspondent and "Dancing with the Stars" competitor JULIANNE HOUGH. "One day they were talking about it and they said to me, 'Would you like to write the music? We are going to do a play.' I said, 'After all this time?' You never know when something gets started what it is going to do."

The 'Nine to Five' musical will star MEGAN HILTY in the role of Doralee Rhodes made famous by Dolly, ALLISON JANNEY is taking over from LILY TOMLIN as Violet Newstead, JANE FONDA's Judy Bernly will now be played by STEPHANIE J. BLOCK and the role of Franklin Hart Jr. (DABNEY COLEMAN in the movie) has been awarded to MARC KUDISCH.

"When we did the casting it was obvious these were the ones," the country queen continues. "I am very excited about it. Today we were taking pictures and it was a flashback to 27 years ago when Lily and Jane and I were taking the same pictures."

As ET has earlier reported, Julianne has been busy in Nashville recording her first solo album, so she couldn't resist asking Dolly for advice.

"The best advice is be true to yourself," Dolly says. "Know your own talents. Know your own strengths and weaknesses and don't sell out to anybody."

Dolly can also be seen Tuesday night on "American Idol" when she is the first celebrity mentor of the season.