Just the time for test Indexer, input is a link to play a song, output is info of that song. Currently, I am testing some other music sites and coding for music-engine on the server-side.
You can test the Indexer at: http://musicengine.byethost13.com/
Free host :).
Thinking so much about an OpenSocial apps and finally I decided to develop a music-engine application.
What is a music-engine? My music-engine will crawl and index as much as possible any songs in the Internet and reorganize it into datastore in Google Apps.
Music-engine will be the service provider allows me to write OpenSocial apps for any container. Users can search, listen, create and save their own favorite playlists. They can send that playlist to their friends as gifts.