Thanks very much for your helpful reply!
Sorry I neglected the Moodle version: 3.7.1. And, yes, I can install plugins.
The Checklist sounds very interesting!
I am aware of the Music Theory plugin... I already planned to use it; it looks really cool. And, I do understand already how to use most of the "activities/resources". There's a lot there. I already installed H5P and I intend to use it extensively.
I got your private message! I'll be answering you soon. Thanks again!