Guitar Hero: On Tour is acting wonky.
Here it is: http://www.vgchartz.com/games/game.php?id=16432
Here it is again, this time with just Japan sales: http://vgchartz.com/games/game.php?id=27372®ion=All
Which is how it shows up when you search for it: http://vgchartz.com/games/index.php?name=guitar+hero&console=DS®ion=All&developer=&publisher=&genre=&keyword=&boxart=Both&results=100&order=Sales
"[Our former customers] are unable to find software which they WANT to play."
"The way to solve this problem lies in how to communicate what kind of games [they CAN play]."
Satoru Iwata, Nintendo President. Only slightly paraphrased.