'Mickey wrote him a very long, heartfelt letter,' director Darren Aronofsky says of Golden Globe-winning song.

Finding music for a film isn't typically an actor's job, but in the case of Bruce Springsteen's theme song to "The Wrestler," which won a Golden Globe last night for Best Original Song, the Boss has actor Mickey Rourke to thank for adding yet another trophy to his collection.

In a conversation last month with Kurt Loder, Rourke and "Wrestler" director Darren Aronofsky shared how they convinced Springsteen to pen the tune — for nothing. (Head to the Newsroom blog to find out how Rourke got Axl Rose to give them a good price on "Sweet Child O' Mine.")

"Mickey knows the Boss from years ago," Aronofsky said, "but they haven't been in touch during Mickey's lost years. ... And Mickey wrote him a letter — a very long, heartfelt letter — and sent him the script."

Obviously Rourke — who also won a Golden Globe last night, for Best Lead Actor in a Motion Picture Drama — was willing to put his heart and soul into making sure "The Wrestler" would succeed. In what is being considered a major comeback for the once-forgotten actor, the role is now making him a favorite for an Oscar nomination.

Apparently his letter-writing skills are quite good, too. According to Aronofsky, "The Boss called Mickey in the middle of the night and said, 'I'm in Europe and I'm touring, and I don't know if I can do this, but if I can, I'll try something.' "

About a month later, the duo went to see Springsteen in concert at Giants Stadium. After Rourke introduced his director to the Boss, Springsteen picked up his guitar and proceeded to play the now award-winning tune.

"I literally got stage fright," Aronofsky said. "I never knew what stage fright was! My chin just went down, and I said in my head, 'Oh my God, I'm freezing up in front of Bruce Springsteen.'"

"Then he played the song," said Rourke.

"Right," said Aronofsky. "Then we started talking, and then he played the song, and it was amazing. And he's like, 'I don't know if it's good yet.' "

Apparently, the Golden Globe voters thought it was!

"Anyway, he's a normal guy," Aronofsky said. "And then he gave us the song for free."