To use Solfeo.app:

   1.  Press "Start"

   2.  Press "New Note" or tap the key "a"

   3.  Respond to what you see on the music staff by 
       pressing the appropriate button:

       	  Do, Re, Mi, Fa, Sol, La, Si, ...

       or by tapping the key:

          d, r, m, f, s, l, w


You can adjust the sliders to restrict the range of notes
displayed.