When you see the star for middle C4 if it is to the right of the piano then you move your cursor to the left and start your tune at the left C2, and I believe that D2 (low bass) is the first note. When you are finished move your cursor to the right(a small arrow appears) and start the second part of the tune to the right of C4 when you hit the last note that is the star C4. Hope this helps