Unless you plan to narrate your slideshow, playing carefully selected songs from your iTunes Library during the slideshow can enhance the presentation.
To select music:
For saved slideshows, click the Music button to open the Music Settings dialog; for basic slideshows, click the Music tab in the Slideshow dialog.
Select Play Music During Slideshow.
Either select a playlist from the list above the songs or a song from the song list (Figure 5.3).
Figure 5.3. Pick either an entire playlist or a song to play during your slideshow.
You cannot select multiple songs at once. Until Apple addresses this limitation, the only way to play multiple songs is to select an entire playlist (select the playlist and don't select any songs in it).
To search for a song, enter the first few characters in its name or the artist's name in the Search field. iPhoto narrows the list as you type. Click the X button to clear the Search field and expand the list.
To sort the list of songs, click the header of the Song, Artist, or Time column; sorting by time makes it easier to match the music to your slideshow's length.
Click the triangular Play button to play the selected song; click it again to stop. You can also double-click a song to play it.
If iPhoto doesn't pick up the sort order of a playlist from iTunes correctly, quit iTunes.
More Slideshow Music
iPhoto can play any MP3 or AAC file you have in iTunes, along with AIFF and WAV files. You can create MP3 and AAC files from your audio CD collection in iTunes, or you can download (legally!) MP3 files from the Internet; search with Google (www.google.com).
Depending on your Mac and your music skills, you may be able to use Apple's GarageBand software to create instrumental tracks for playing during slideshows. GarageBand comes with new Macs and is included in the iLife '06 suite along with iPhoto.