For a start I'd suggest a midi file to keep the file size down. I'd also suggest that you rethink the idea on the whole. Sound on web pages is one of those things that you either love or hate.
Guess which bracket I fall into ?
Assuming your file is a midi file and is called bgsound (stands for back ground sound) you can use the following code:
<embed src="bgsound.mid" hidden="true" autostart="true" loop="1">
<noembed>Your browser doesn't support EMBED, but you can still listen to the background sound of this page by a href="bgsound.mid" clicking here.</a></noembed>
I've removed the <>from the a href= link to allow it to display in this page properly.
src="" is the source of the sound file - this is the filename and the folder it lives in in your web.
autostart="true" tells the web browser to start playing the file as soon as it is loaded or setting the value to false means your visitor can choose whether or not to listen to it by clicking the hyperlink you provide for them.
loop="1" plays the sound once. You can either use a number to specify how many times the sound plays, or you can use true or false.
Hope this helps.