how do i get a song to play throughout the entire powerpoint presentation w/o it starting over on each slide?

Question

it's a .wav file

Answer 1

To play a background music loop or music file across a number of slides in PowerPoint 20002/XP 2003, and 2004:
Choose "Movies and Sounds" from the Insert main menu option.
Depending on your preference, select "Sound From Clip Organizer", or "Sound From File", or "Play CD Audio Track", or "Record Sound".
Locate the Sound file that you wish to play across any number of your slides.
Insert the sound.
If you don't want the sound icon to appear in the presentation, drag it off the slide.
If you are asked Do you want the sound to play automatically? Select "YES".
Right click the sound's icon and select "Custom Animation" from the popup menu. The Custom Animation dialog box will open and your sound file should be listed.
Click the arrow directly to the right of the sound icon to pull down various options.
Select "Effect Options", and on the Effects tab, Select the radio button beside "Stop Playing after XXX slides". Select the number of slides that you would like the music to continue to play through. If you want the sound to continue through the end of the presentation, enter a very large number, for example 999.
Select the Timing tab. To play automatically, the timing should be set to Start After Previous with a 0 second delay.
Click OK to close the dialog box.
Your music track will now continue after you leave the slide on which you placed it and play until it reaches the slide number which you entered to Stop Playing.

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To play a background music loop or music file across a number of slides in PowerPoint 97 and 2000:
Choose "Movies and Sounds" from the Insert main menu option.
Depending on your preference, select "Sound From Gallery", "Sound From File", "Play CD Audio Track", or Record Sound.
Locate the Sound file that you wish to play across any number of your slides.
Insert the sound.
If you don't want the sound icon to appear in the presentation, drag it off the slide.
If you are asked Do you want the sound to play automatically? Select "YES".
Right click the sound's icon and select "Custom Animation" from the popup menu. The Custom Animation dialog box will open and your sound file should be listed.
Select the "Multimedia Settings" tab, making sure that the sound object is selected.
Click the checkbox, placing a checkmark next to "Play using animation order".
Select the "Continue slide show" radio button. This allows PowerPoint to continue playing the sound when you move to the next slide in the presentation.
Beneath Stop Playing, Select the number of slides that you would like the music to continue to play through. If you want the sound to continue through the end of the presentation, enter a very large number, for example 999.
Click the "More Options" button, and click a checkmark in the "Loop until stopped" checkbox.
Select the Timing tab. To play automatically, the timing should be set to Start After Previous with a 0 second delay.
Your music track will now continue after you leave the slide on which you placed it and play until it reaches the slide number which you entered to Stop Playing.
Remember that only .WAV audio files can be embedded into your presentation. PowerPoint merely creates a hyperlink to all other sound types including MP3, CD-Audio, MID, RMI, AIF, AIFC, AU, WMA, and AFS. And that while PowerPoint 2000 supports all forementioned sound formats, PowerPoint 97 does not support MP3, AIF, AIFC, AU, WMA, and AFS sound types.

Answer 2

Attach it to only one slide (the first one). If you add the same title to every slide, it will start over on every slide.

View the animation properties, select "effects..." and select the "effects" tab on the resulting dialog. Verify that the "stop" conditions (after click, after this slide, etc.) are set appropriately.