Writing about "Cliffs of Dover" recently made me think about Guitar Hero, and how awesome it could have been. I think it's great that Guitar Hero and Rock Band have gotten kids enthusiastic about music they might not otherwise have been exposed to, but I wish these games actually taught people how to play an instrument instead of a plastic controller.
The thing that makes teaching such an interesting challenge is that you must find the sweet spot where something is challenging enough to keep the student engaged, but not so challenging that it makes you want to give up.
This is what video games do marvelously well, and what makes them so addictive. You have a perfectly graded learning curve, with new information being added all the time in just the right dose.
The technology certainly exists to create a video game that will actually teach you how to play an instrument. While there are games that were created for an educational purpose, none are as perfectly sequenced or on as grand a scale as Guitar Hero.
Imagine a game in which education and entertainment are perfectly blended, with the big budget and classic songs that Guitar Hero and Rock Band have. Imagine the gamers of the world putting those vacant hours every day into learning a real skill. We would have an army of real guitar heroes.