There's a lot here that's impressive, but I am fascinated by (and a little jealous of) people who can yodel. Do you think it's a natural gift, or can people be taught?
Aw, anyone can do it... It was how folks hollered to each other back in the day. That's what folks do wrong, trying. Too timid. At least when starting, you've got to mean it - Belt it out. Kinda like gulping water backwards... without the vomit.

Really have to open the throat.
Also, re the stringed instruments you play... can you read music, or do you play by ear?
Nope. Can't read a lick.

Just picked up a guitar one day and never put it down. Learned pickin on Wildwood Flower... My folks still can't stand that song, I'll tell you what... Picked up the rest as I went along, and went semi-pro... played bars and honkytonks for a while, and was in the house band for a small recording studio...
Then life happened. Figured out I hit my limit, and like wrangling horses, there just wasn't any money in it.