While this kind of video works pretty well with the simple ambient sound that goes with the images, sometimes it's better to drop in a more professional soundtrack.
Click the Audio button and access your iTunes playlists.
Position the playhead in your timeline at a point where you want the music to start.
In this case, starting at the beginning is logical, but on some videosthose with titles, for instanceyou might want to start the music midway into the title display, or after the title appears but before the video images start. Regardless of where you drop the music, you can easily slide it around afterward if you don't like the location.
Select a track to add to the video.
Click Place at Playhead, or just drag the name of your song to your timeline.
iMovie will import the clip, and a purple bar will appear on one of your audio tracks.
If the song is longer than the video track, cut it off after about 1 second following the end of the picture, using Command-T, and delete the tail.
If you're using GarageBand to generate a background track (Lesson 12), use the duration of the project in iMovie to guide your music creation. In this case, the video project is 1 minute, 15 seconds, 24 frames long. Round it to 1 minute, 16 seconds, and use that as your guide in GarageBand. The most important aspect of background music is the mixthat is, the balance between the loudness of the music and the loudness of the audio track of the video.
Click the volume percentage menu at the bottom of the iMovie window.
This lets you change the volume of the entire track by using a pop-up slider (or typing in a percentage) or change the volume at precise locations in the song by manipulating points on a line. For now, just change the volume of the entire track to 35 percent, which is in the appropriate range for a background track, although it truly depends on the music.
To change the volume at specific points within the track, click the line superimposed over the audio track. Big yellow dots will appear on the line. You can then raise or lower the volume at one of these dots without changing the entire track's volume. By choosing these dot locations carefully, you can achieve an impressive sound mix. More on your sound mix in Lesson 12.