I'm trying to decide which mime type to choose for returning mp3 data (served up by php)
according to this listing of mime types: http://www.webmaster-toolkit.com/mime-types.shtml
.mp3 audio/mpeg3
.mp3 audio/x-mpeg-3
.mp3 video/mpeg
.mp3 video/x-mpeg
What are the difference between these, and which should I use?
Your best bet would be using the RFC defined mime-type audio/mpeg
.