Theory is fun. I'd forgotten how interesting and satisfying writing a fugue can be.
The performance is a computer rendition. To be playable with two hands I'd need to transpose the left hand starting at mm. 8., but then it wouldn't sound as rich.
If you would like some help with music theory call me.
You've got to learn your instrument. Then, you practice, practice, practice. And then, when you finally get up there on the bandstand, forget all that and just wail.
I'm a professional pianist and music educator in West Toronto Ontario. I'm also a devoted percussionist and drum teacher.