Joseph Gordon-Levitt shaves his head with the musical accompaniment of Cut Copy's 'Where I'm Going' in the trailer for the new movie '50/50.'

Gordon-Levitt is a proven Nirvana fan, but in the trailer he shaves his head to the pounding beat of the Cut Copy tune, despite the pleas of his friend, played by Seth Rogen, who says. "Please don't do this ... You're gonna look stupid." The trailer shows the serious and comical sides of the movie, which depicts Gordon-Levitt's character receiving a cancer diagnosis and Rogen getting a medical marijuana prescription.

'Where I'm Going' appeared on 'Zonoscope,' the most recent release from the Australian electronic band. It's the most prominent of several song clips used in the trailer. Also featured is 'Carries On' by indie folk act Edward Sharpe and the Magnetic Zeros.

'50/50,' which also features performances by Anna Kendrick, Anjelica Huston, Bryce Dallas Howard and Serge Houde, hits theaters on Sept. 30.

Watch the '50/50' Movie Trailer