If you think the "illustrated" slides are no longer new, add the sound to the slide so you can demonstrate it with a wonderful musical accompaniment. But if you just insert a sound inside the page, the sound stops when the next slide is shown, and the following settings allow the music to play until the demo is finished. After you run PowerPoint2007, open the PPT document that we need to edit, and then on the Insert tab, select Media Clips-sound-file sounds, open the Insert Sound dialog box, find the music file you want to add, and then click OK ( PowerPoint2003 select "Insert → movie and sound → file sound"), in the following window if you select "On click" then the sound will play only when clicked at the show, so select "Automatic" here, as shown in Figure 1.
In order to achieve the loop play also need to be further set, PowerPoint2003 right click on the document appears on the "small horn" after selecting "Edit Sound Object" and check "loop until Stop", PowerPoint2007 can be checked in the "Options" tick "" loop until stopped , and you can also set the volume of the slide show, and so on. This method is ideal for use when adding soft background music to slides.