Movie Addict Penelope Cruz

Penelope Cruz found working on 'Nine' addictive.

The 'Broken Embraces' formed a strong bond with her co-stars on the musical, which included Kate Hudson, Nicole Kidman and Marion Cotillard, and particularly enjoyed their dance training.

She said: "It was scary, but it was so much fun. It was great seeing that we were all feeling the same way. There was a great support system on that set, all the actors with each other and with Rob Marshall, the director.

"I had danced classical ballet before, so this was very different from what I had studied. We had a room in our building and we were all taking different classes. We would all pass each other in the hallway. All day, training. We all felt so free and so happy. Music was so present everywhere. That elevates people, music. It was so addictive, that experience."

Movie addict Penelope Cruz

Rob admits he was amazed by the actress' work ethic and dedication to giving the best possible performance while filming.

He explained: "She knew we had to get in there and really be great, so she came in and worked like nobody's business. She was the first one there and the last one to leave. She'd always want one more take. She's a real perfectionist."