You can import any iMovie project or QuickTime-compatible video file from the Media Browser and add it to a track in your GarageBand project. This allows you to view the movie while your GarageBand project plays.

To import a video file using the Media Browser:

1. In the Media Browser, click the Movies button.
2. Select the movie you’d like to score.
3. If available, double-click the movie file thumbnail image to preview the movie in the Media Browser.
4. To stop the movie preview, press the spacebar.
5. Drag the thumbnail image into the Movie Track in your GarageBand project. GarageBand generates thumbnails for the track to represent the video clips. It also adds a track called Movie Sound, and creates a new AIFF file that contains the soundtrack of the movie. The original movie file remains unchanged.