Here's a free online audio converter that makes it easy to convert from one audio format to another.
If you need instructions for coding a new HTML 5 audio player, I suggest visiting this site.
The simple code for implementing an audio player in html 5 is:
<audio controls preload> <source src="http://yourserver/rockandroll.ogg" /> <source src="http://yourserver/rockandroll.mp3" /> </audio>
I recommend that you you create audio files in mp3, ogg and wav formats to ensure that your player will work in any browser.