The trick is just to do what seems to work and then see how you can sneak in the general fundamentals. Everyone's different and 3 years old is very young. You have a lot more options as a parent than a teacher who meets a kid once a week, though.
Keep it fun, but add traditional skills if possible, obviously at the right pace and level, because those fundamentals become a big part of the motivation the older one gets. It's not how much or what level one does that stuff on. It's mostly just knowing that it is a thing that the "grown-ups" actually do.
He seems to get the feel and song structure, so maybe try something different. Buffalo Soldier tends to be my next go to.
When he's that into it at that age it's a great chance to expose him to as many types of music as possible. Just listen to a bunch of stuff and whatever he likes find a way to play it.