Aside from a live stream, your original question is about a player starting up. Playlist.com has a really good selection of tunes, and you can set your player to start automatically when someone visits your page. I have three players depending on what kind of mood I'm in (or my partner, for that matter), but I have only one of them on autostart, because all three would auto-start otherwise.
You should know, as welll as anyone else, that Firefox now has an add-on that prevents auto-start on all players!
How peaceful that is....
I will show you fear in a handful of dust.
"The Waste Land" T. S. Eliot