[Zombie Machairodont]

I really encourage the use of a start/stop button on a webpage, and in full view at the top of the page so that visitors don't have to search or scroll to find it. Overall, I don't mind webpage music (as long as it isn't too much) and can add a nice touch when it is a subtle bit of ambiance. If I'm listening to my own music, however, I usually want to be able to turn off a webpage's music so that I can keep listening to my own. Just my two-cents.

 

[Zombie Machairodont]

nightrideproductions has a very good point. Make sure that what ever music you put up (if you do) isn't going to be jarring. Songs that seem to start loud or have a big "POW" of noise can be a little unpleasant if you don't anticipate it. Which is why I suggest ambient stuff like Midnight Syndicate or Nox Arcana-type tunes for a site.
I completely forgot to say your site looks great! Quite easy on the eyes and nicely organized.