You can add any audio file as background music to your project. Background music plays behind the audio recorded with your video and any sound effects or voiceovers you add to video clips.
If you want to add music to just a specific clip in your project, go to this topic: Add a sound clip to your project.
To add background music:
With your project open in the Project browser, click the “Music and Sound Effect” button in the toolbar below the viewer, or choose Window > “Music and Sound Effects.”
The Window menu appears in a light gray bar across the top of your computer screen.
Choose one of the music options from the pop-up menu at the top of the browser—Music, iTunes, and so on—and then browse to find the music you want to use in your project.
If you don’t see the pop-up menu, drag the gray dot (shown below) upward to reveal it. You can also use the search field at the bottom of the browser to find an audio file by name.
Drag one or more audio files to the dark gray area to the right of the last clip in your project, making sure you don’t drag them over a clip.
Release the mouse button when you see a green Add (+) symbol.
The background music well of your project is then shaded with green, representing the background music clip. The music begins at the start of your project and ends with your video, even if the song is longer than your video.
If the song is longer than your video, a music indicator (a musical note symbol) appears above the last element in the Project browser. If you add more video clips to your project, the background music extends to encompass them, until you’ve reached the duration of the music.
If the music doesn’t cover your entire video, you can add more music by dragging it to the background music well of your project. When you add two or more background music clips to your project, iMovie automatically adds a one-second cross-fade between the clips where they meet.
If you want the music to begin somewhere in the middle of the song, or if you want the music to end before the end of your video, you can set the startpoint and endpoint of the background music using the Clip Trimmer.
If you want the song to begin playing somewhere in the middle of your movie, you can pin it to any video frame.
To adjust the volume of background music:
Click the Action menu (looks like a gear) in the upper-left corner of the green background music well, and choose Audio Adjustments from the menu that appears.
In the inspector that opens, drag the volume slider, which appears at the top, to the right or left to increase or decrease volume, and then click Done.
To delete background music:
In the Project browser, click to select the background music well; it becomes outlined in yellow.
Press the Delete key, or choose Edit > Delete Selection.
The Edit menu appears in a light gray bar across the top of your computer screen.