Every so often, a special movie emerges that features not only great dialogue, but also a song performed by the actors that makes a cultural impact. In many instances, the tunes from the soundtrack are by outside musicians, such as Green Day's "21 Guns" in Transformers: Revenge of the Fallen, or "Gimme Shelter" by the Rolling Stones in Goodfellas. However, these songs performed by the actors play a major role in the film itself.