hey.. nice idea and i have a few suggestinos
i did only lesson one, so i don't know if what i say is for everything
the lesson went slowly!!!!! you should try making it in powerpoint format so if you click it goes to the next text.
and i felt stupid for doing the lesson,but i don't know if that's because of the language or because i know the circle.

Thank you verry much I understand it now.
I love learning new things and yhis is
something that i will use.
Thank you

<Added>

having it in bass clef, tenor clef and alto clef would be great.