Thanks for the comments, Jack and Kevin. One of my sources was Gracenote itself -- specifically, the claim here that "when iTunes consumers search for information about an artist all of that information comes from Gracenote. " Is it true? I doubted it too, specifically based on my own experience editing metadata, which is why I wrote "largely" in my original post.

Kevin, regarding your second and third points, Gracenote has a years-long lead over the commercial competitors, and, as you note, there haven't been any "realistic alternatives to Gracenote until recently." I have to question how the competition can catch up to Gracenote, in terms of matching the breadth of holdings. If you have data that quantifies the holdings of the different services, please feel free to share.

The point you bring up about Sony monitoring iTunes is a serious one, and should be given credence, not just because it's a multinational corporation that already wields enormous power, but because of the poor lack of judgment it showed with the "rootkit" software.

Lastly, Jack, if Apple wants to change services, or build their own, of course it can done. But I want to question your statement that it can be done "easily" -- you seem to have some insights here, I'd like to know exactly what you think is involved.

Also, are you claiming that Sony doesn't have any leverage over Apple with the Gracenote purchase?