By default there is no sound during a picture slideshow. You can add a specific song from iTunes to play while watching pictures.

To get started:

• Make sure the sharing checkbox is enabled in the Sharing pane.

• Click the "Change Song" button in the Pictures pane.

• Scroll or search for the song you want and select it.

• For AAC files, the songs will be prepared for streaming first and cached.

Learn more: Media Sharing, AAC Music Files.