I've found the claim that Chrome "will play most stuff thrown at it" to be a false one. Here's a Chrome bug I discovered last month while hacking a Flask application:

  mkdir static && wget http://www.soundjay.com/button/beep-1.mp3 -O static/beep.mp3 && python -c "import flask; flask.Flask(__name__).run()"

Then hit: http://127.0.0.1:5000/static/beep.mp3

The mp3 plays fine in Firefox (not natively of course), but doesn't play at all in Chrome. The same problem extends to the HTML5 audio tag (eg. <audio src="static/beep.mp3" />).