[ Ref. 250610 MMD and https://www.ebay.com/itm/267284832588 

I believe this is a music classroom chart or private piano lesson
chart that will line up with the keyboard on any 88-note piano.

Looking at the photos, it starts with low A, the lowest note on
a standard 88-note piano. In my opinion the chart is an aid for
a beginning piano student. Match it up to a keyboard.

John Bartlett
Woodruff, South Carolina