If you have QuickTime Pro, you can use QuickTime Player to convert files from an MP3 music file into QuickTime movies.
In QuickTime Player:
1. Choose Import from the File menu. Locate and select the music file you would like to use then click Open. The music file will open in a new QuickTime Player window.
If you will be adding the music to an existing movie, continue with the following steps:
1. Choose Open Movie In New Player from the File menu. Locate the movie you want to add music to and click Open.
2. Click the music file window to make it active and choose Select All from the Edit menu.
3. Choose Copy from the Edit menu. This will copy the entire song into memory for adding to the existing movie.
4. Click to make your existing movie the active window.
5. Choose Add from the Edit menu. If you don't see Add under Edit, then hold the Option key (Mac) or Ctrl and Alt Keys (Windows) on the keyboard. While holding the keys, go to the Edit menu and choose the Add. (In the Edit menu, the item normally labeled Paste changes to Add when holding the Option or Ctrl and Alt key.)
6. Choose Save As from the File menu. A "Save" dialog box will appear. Enter a new name in the "New file name" box. Next, select the radio button labeled "Make movie self-contained" and then click the Save button.