As I mentioned earlier when talking about sound effects, there are many companies that provide royalty-free music and audio clips. iMovie can import any audio files that are supported by QuickTime.
To import an audio file:
Position the Playhead in the Timeline Viewer where you want the imported file to begin.
Choose Import from the File menu, or press Command-Shift-I.
In the dialog box that appears, navigate to the audio file (Figure 10.29). Click Import.
Figure 10.29. Locate an audio file. iMovie reads any formats supported by QuickTime.
Wait several seconds for the file to be imported, then be amazed when it shows up as an editable audio clip in the Timeline's track 2 (Figure 10.30).
Figure 10.30. iMovie automatically places imported audio files into track 2 in the Timeline Viewer.