Fallback To The Default If Source Is Invalid In Audio Tag

So I have a basic audio element. Say I have a single mp3 source. I'm using Firefox. The browser sees the audio tag, likes it, places the controls as directed, but doesn't like a

Solution 1:

Use the source tag to define multiple file types.

<audiocontrols="true"><sourcesrc="demo.mp3"type="audio/mp3"><sourcesrc="demo.ogg"type="audio/ogg"><sourcesrc="demo.aac"type="audio/mp4"><!-- If no support at all. -->
    HTML5 audio not supported 
</audio>

http://msdn.microsoft.com/en-us/library/gg589524(v=vs.85).aspx