You will need
  • - computer
  • - Power Point
  • - the music file that you want to use
Copy the music file to the same folder where the presentation is saved. This is optional, but will save in further problems with music playback, especially when you transfer the presentation to another computer.
Open the presentation and select the slide from which you want to start the sound.

On the Insert tab, in the group "Multimedia" click on the icon "Sound".
File Explorer opens. Locate the file and click OK.

At the request of the program: "to Play a sound when the slide show?" select Automatically".

All music file is inserted.
On the quick access toolbar in the "sound Settings", check the checkboxes to play "Continuously" and "Hide during show." You can also adjust the volume.
Ready. Have you configured the audio in one slide.

If you want to keep the music going during the whole presentation, go to the next step.
Select the tab "Animation" and click "custom animation".

In the task pane "custom animation" panel in the right part of the screen) click on the arrow to the right of the music file, select "effects Parameters".
There is a window setting play.

Select "Finish" — "After" and insert the slide number, after which the music should stop. For example, after the last slide.

Now the music will sound background for the whole presentation.