This article will explain how to add music to a Picasa photo album or slideshow, allowing you to bring an added emotion or energy to your presentations.
Add Music to a Picasa Web Album
Open Picasa and either select the album you'd like to edit, or create a new one.
Next, click on the Create menu and select Movie:
Click the Upload button. In the window that opens, find the audio file you would like to use as background music. Click on Open.
Finally, click on Make Movie. After your movie is created, you may find your album in the Google Projects section of your Picasa interface.