Roadies is being hotly tipped to be a smash when it hits small screens in the United States later this month. It also stars Luke Wilson from The Royal Tenenbaums and Imogen Poots from 28 Weeks Later.
Castle-Hughes said working with Oscar-winning writer/director Crowe is a dream job.
"Cameron is the guru of this world of rock and roll and music," she said. "It is so nice to be working in the hands of someone who believes in that and believes in the stories and is still doing it at a grass-roots level, despite his success.
"It is my ideal working situation. I love it."
Roadies is not Castle-Hughes' first foray into the world of music.
Last year she teamed up with Kiwi entertainer Mika in Los Angeles to record her debut single.
Castle-Hughes has also indicated she has no idea if her character on Game of Thrones will last another season.
"The craziest thing about the show is we are almost as in the dark as anyone else," she said. "I actually learn more from the fans than I do from working on it."
Roadies starts on July 4 at 8.30pm on SoHo.