The XSPF Web Music Player lets you play MP3 playlists for your blog visitors. It it reads in a XSPF file to play the MP3s listed in the file. XSPF is the XML Shareable Playlist
You can learn more about XSPF here: http://www.xspf.org/quickstart/ or use a service like http://www.ilike.com to generate one.
When creating an XSPF file, your WEBSERVER must be configured to serve .xspf files with the MIME type "application/xspf+xml".
If you put a .xspf file on a regular old webserver it won't work; it will serve the file as MIME type "text/xml" instead of "application/xspf+xml".
This player was developed by Fabricio Zuardi and is available in other configurations from http://musicplayer.sourceforge.net/