I'm glad somebody else spotted the reality of it. Some of us don't like getting caught up in the rote memorization and learning aspect; that's not the meat of any experience. Sure, you can have fun when learning, but let's be honest: what was more fun, learning to ride a bike, or actually riding the bike on your own?
Wii Music is genius because it breaks away from the critical flaw of the game industry: the focus on teaching how to play instead of giving the experience sans training. Actually, all of the Wii series of games are good about that. You don't have to know how to play any of the sports on Wii Sports, the minigames in Wii Play need only 1 sentence each to describe how to play them, Wii Fit is perfectly intuitive, and even Mario Kart Wii is easy to play and requires no knowledge of how actual driving works to enjoy.
It's easy to make a complex experience that requires a lot of training to fully appreciate. That just requires time, energy, and no real creativity. But to make a simple experience that requires no training to appreciate, yet is intuitively fun... That is not so easy to pull off, though I'm sure many would argue it is. And to them, I say this: try and replicate the success of the Wii series with the same "simplify and perfect" mentality on something the Wii series has not touched on, and get back to us on how easy it actually was.
Sky Render - Sanity is for the weak.
