This tip should be used right after the <head>:
Insert this code onto ONE line:
<bgsound src="http://home.comcast.net/ nilsmolina/Hecho.wav" loop="-1">
And you will get background sound like this.
Change the url for a different sound location.
Change the loop number if you would like to specify the amount of loops the sound should play.
That is how to add background sound.