Where to discuss songs?

I often seem to wonder about the meaning of songs, and would like to talk about them with others. Consider the track "Dragon Queen" from the latest album from Yeah Yeah Yeahs, It's Blitz! It's a catchy track, but there are some indecipherable lyrics in there, and it sounds very much like another popular song which I can't quite identify. I think it would be fun to argue about the lyrics and identify the funk track that Karen O and friends are lifting.

Allmusic has the data on this track - how long it is, who made it, etc - but offers no forum for discussion.

Where should such a form exist? Should it be a feature of an existing service (like allmusic), or should it be it's own thing? Should songs have a canonical URL?

Some songs are important enough to warrant a wikipedia article, but Dragon Queen is really not one of them, I think. And besides, wikipedia is not appropriate for critical discussion. So for existing services, I think Wikipedia is out.

A great place for online music discussion would be Allmusic - they already have all the facts handy, all that's needed is a new discussion feature. I'm not sure what their revenue model is, but traffic is always good. Last.fm would be a nice place for this kind of musical discussion, too. Of course, if Google could somehow collect all the blog posts, tweets, and comments about the song from all corners of the web, that would be very impressive! YouTube is another option for music mecca, but the song has to have a video associated, and frankly the quality of youtube comments is so bad I wonder if this would be worth the cost.

There are so many options for musical discussion, it's surprising it hasn't really happened yet.

[Update: it turns out that Last.fm is the place. It has all of allmusics info, and you can edit entries for artists, albums, and tracks, and forum discussions. For example, here is the page for Dragon Queen. Last.fm calls comments "shouts", and their OSX thick-client doesn't support them, which is why I missed them on my first look at Last.fm.]