I have argued that Commerical Off the Shelf Games Will Not Work in Education. This position may need to change in light of the following program. But I am no music teacher, so I don't know how useful it may be.
MaestroLive is a Music Game. From the website:
MaestroLive is a music game that lets anyone play songs by tapping the rhythm of the song on a computer keyboard or on an attached MIDI keyboard. MaestroLive gives you a score for your performance. When you finish playing a song you can save your score to the MaestroLive network and compare it with previous scores of that song or with other player’s scores. Each song has its own set of scores.
# Choose a song from the MaestroLive Song List.
# Pressing any key on your computer keyboard will play the correct next event (an event is a single note or a group of notes).
# The rhythm radar in the center of the MaestroLive window provides you with a visual indication of when to play the next event.
# By pressing the computer keys in the correct rhythm (using the rhythm radar) you will be playing the song.
# You’re performance score updates while you play – when you finish playing the entire song you can save your final score to the MaestroLive network and compare it with the scores of other players of that particular song.
# MaestroLive can also teach you how to play "for real" if you attach a MIDI keyboard to your computer.
But you must download a program first in order to use it. It is free.