<audio> and <source>

The audio tag and the video tag can each be written as a cascade of file types. The browser tries the listed files from first to last stopping at the first file that it can play.There was a bug in Firefox that kept it from following the cascade if the first file was an mp3. That seems fixed in the current Mac version, on which Firefox plays the wav. The code looks like this:
<audio controls autobuffer autoplay="false" style="float:right; margin:0 2em;">
<source src="images/mp3.mp3" />
<source src="images/aif.aif" />
<source src="images/wav.wav" />
</audio>

The attributes autoplay and loop are also available.