I am with Clint Hammond on this--don't do the background thing--it is more than annoying--streaming audio takes up extra bandwith and can slow down and even lock up a browser if any of the related servers are overloaded--

also, background music can play even when the page is in the background--sometimes I've had music from three or four different pages start to blare at me at the same time because I didn't realize that there was streaming music attached to the pages I was opening--

If you want, you can give people the option of opening a music stream when they are on your page--