This is a well-stated argument for a more-reasonable, finite duration for copyright.
What I find most fascinating right now is that it just feels right to me that a video game should have a shorter copyright duration than a song, although I’m not sure exactly why I feel that way. Songs seem to have a longer cultural relevance.
http://www.osnews.com/story/27551/Why_games_should_enter_the_public_domain
Unpopular and/or obscure content of any kind is limited in its revenue potential.
I suspect that popular music can generate significant royalty revenue much longer than any video game.
With tracks available a-la-cart this is more true now than ever before, since profit margins on individual tracks are often higher, and track prices are generally discounted less than album prices.