"AN experience of a lifetime” is the only way Stanthorpe girls Hollie Brunckhorst and Susie Cobon could describe performing as part of the Grease Arena Spectacular last weekend in Brisbane.

They were part of a mass ensemble of 650 people performing in two shows in front of thousands of people at the Brisbane Entertainment Centre.

The girls performed alongside theatre professionals Christine Anu, Beau Ryan and Thomas Lacey and other ensemble members from all across Queensland.

Brunckhorst said the atmosphere of the show was really exciting.

"I've done a lot of theatre before but it was so large scale and there were so many other people who really wanted to be there,” she said.

"We didn't get tired during the performances because there was just so much excitement,” Cobon said.

Leading up to the performance the girls went into two weeks of intensive rehearsals, working in blocks for the first week then 8am-4pm every day of the second week.

Brunckhorst injured her knee in the first week of rehearsal but strapped it up with a "show must go on” attitude.

"I had to have the straps underneath (my costume),” she said. "The energy that was kept up for the whole thing made it a lot easier to push forward.”

Cobon said she especially enjoyed the technical rehearsals on the two days before the opening show.

"We got to go to the arena and perform with the principle cast, it felt like it was real,” she said.

"Just being there and seeing all seats and it was just incredible.”

She said learning from the professionals performing with them was a highlight of the experience.

"If you saw them in the hallway, they'd always talk to you which was good cause you could connect with them easily,” she said.

"There was one (dance captain) who was really confident in herself and she had so much energy and that really helped me.”

"We learned the way you treat people in the industry really reflects on you,” Brunckhorst said.

"If you're rude to people, you're less likely to be cast in something. It's cemented for me that's what I want to do now.”

The girls both plan to audition for the arena production of The Wizard of Oz next month.