it really is that simple

as promised, have been looking over a few more examples... Here's a nice little tutorial posted on Sept 2nd:

This very short video tutorial shows you how to generate sound with JavaScript in Firefox 4... in under 2 mins! Seven lines of JavaScript code is all it takes to begin programming audio in Firefox 4.

You can download the latest Firefox here:
http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/latest-trunk/

(Pre-releases are called "Minefield")

You can find the code and text-based tutorial here:
http://weblog.bocoup.com/generate-sound-with-javascript-in-firefox-4

and for fun: http://code.bocoup.com/audio-data-api/flash-vs-html5/

next for me? maybe a better look at Processing (which is also behaving strangely - examples no longer load via file menu)