How to control embed (for midi and wave plugin) by JavaScript?

How can I control embed by JavaScript?
I've made a test-page with that code:

<embed src="test.mid"
  width="200"
  height="200"
  autostart="false"
  id="music1"
  name="music1">
</embed>
-----
<script language="JavaScript1.2" type="text/JavaScript1.2">
   document.all.music1. [???]    //<----------
</script>

What controls are there avaible for midi-files? (and for wave-files?)

And I need to know how to change the volume by JavaScript.
This is only a test-code but I want to fade in and out when some actions are
happening.