It would be nice if this music player could 'scrobble' the tracks to last.fm

http://www.last.fm/api

Though it would require a profile field for last.fm username in order to scrobble the track to the correct users account.

I was trying to do this for a while, but as a non developer I couldn't really understand the documentation :P

My two cents: I think this feature would also be useful if it could play single audio files from galleries as well opposed to using a browser-supplied plugin (assuming you're talking about making a music player built in to Composr via. the add-ons or something).

"My two cents: I think this feature would also be useful if it could play single audio files from galleries as well opposed to using a browser-supplied plugin" - it already should be using jwplayer (note not jplayer) for this. jwplayer will either use HTML5 audio facilities (i.e. native playback), or revert to Flash-based playback. Assuming you are using a common format (normally mp3).

"It would be nice if this music player could 'scrobble' the tracks to last.fm"

It is fairly likely that we will be implementing this jplayer task for a client, and scrobbling is much more specific. You'll therefore probably need to open a separate tracker issue for it after this is closed.

Very preliminary implementation (which won't do much) attached.

I've also attached an old 4.3 integration we did for a customer around mp3gallery. There's likely little of value left now, but it might be useful for reference.