Not done this, but it should work.
Take any object and open the format box (right click) Select the sound tab and add the file. This should play the music you need. However it may stop when your naration starts, you will need to try it and see.
Not done this, but it should work.
Take any object and open the format box (right click) Select the sound tab and add the file. This should play the music you need. However it may stop when your naration starts, you will need to try it and see.