The second music game I found is called Break in the Road. This is a great role-play game that has the user acting as a DJ. You are given the task of using your audio recorder to collect environmental sounds from the neighborhood then create a piece of music from these sounds. Once you have collected some sounds you go to the studio and use the multitrack editor to combine the sounds into a new piece of music. When you have your piece of music created you can play it at the local club to find out if the audience likes it.
Both these games are great for having the students play with combining/layering timbres. Other musical elements such as form and harmony can also be addresses with these games as the students are given great freedom to create unique pieces of music.
Andrew