The `Prince of Persia: The Sands of Time` actress dreamed of taking to the stage when she was younger but now accepts the closest she will ever get to achieving her ambition is to portray a musician on the big screen.
She told NME.com: "Music is my biggest passion aside from anything else. I was in lots of dodgy bands growing up and I always fancied myself in a band. But, you know, I was rubbish at writing music. So maybe one day I`ll play a rockstar, or a punk rocker."
However, the British star isn`t interested in landing a role in the forthcoming biopic of Nirvana frontman Kurt Cobain, and believes unknown stars should be cast as the tragic rocker and his widow Courtney Love.
She explained: "Maybe they should find someone new, because when you`re playing an iconic character, if you get someone really famous to play them, sometimes you`re watching someone really famous play someone else, and it`s nice when it`s a completely new person".
Gemma recently admitted she finds it "strange" seeing herself in movies.
She said: "It`s very strange and surreal when I see myself in `Quantum of Solace` or `Clash of the Titans`, especially `Prince of Persia`.
"When I first saw this movie it took me a while to get my head around the fact that I was in it. I was a very normal girl and all of a sudden I`m there with Jake Gyllenhaal. It`s very strange for me and I always saw myself doing theatre and little jobs. I never thought I`d be in anything like this. Now that these films are coming I still find it very strange."