Actually, I don't see why either method would work:
The SWF is in a static HTML page. It requests an mp3, and loads it without
having to refresh. So it needs an mp3 returned, not another SWF.
Updating the DB from the SWF call sounds cool, but serverside wise requires the
.htaccess updated to instruct .swf requests from that dir to be read as PHP.
The PHP script would need to update the DB then open the mp3 and write the
correct headers before returning it.
What's the AMFPHP deal?
Flash Remoting. Action Message Format. Like SOAP but better :D
Tony