I'm a college music professor and I'd like to know how difficult it would be to gain the skills to program something like this? Would going through a basic Javascript course give me enough tools are is this something that would take years to accomplish. http://teoria.com/exercises/md.php

I think it's Javascript.

Just click on the "OK" button to start the exercise. You listen to the musical excerpt, click on note values and enter them on the musical staff.