Your second and third posts to this thread are duplicates of other threads you have created. Please do not create duplicate threads otherwise it becomes very difficult for other users to know which thread they should post their suggestions. You have received the answer in this thread to the first question you posted, because increasing the number of tracks and being able to export to mp3 are both features that you need to buy and download, depending upon which version of Music Maker you currently have (I suspect it is the Free version).
Because of the duplication I am going to lock this thread.