You start right away. Press the key on your keyboard according to the note you see. You will accumulate points wich will disappear. But you can use it to track your progress. The points will not be saved. Press the key space after a session. A session lasts a minute.
I am currently learning how to read notes on a music sheet proper and faster (29.04.2019). I didn't find any good exercises on the internet so I made one myself. Hope this would help you as much as it did to me. This could also be used as entertainment if you may.
