I'm trying out making my youtube lessons

And there’s a program called Slow Downer. My copy was from ronimusic.com

I learn a lot of tunes by ear. It is a skill you can learn with practice. However, I can also read sheet music and sometimes find that a tune can be learned faster that way. There are many sites where folk and traditional tunes can be found in standard notation. We have a list of some good sites somewhere on this forum. thesession.org and flutetunes.com are two good ones. Often if you just Google the name of the tune and pdf you will find sheet music.

I have a series of lessons about the tremolo harp. I sometimes was asked for more graphics and/or charts. I didn't want to invest the time in such things. Somebody else started doing that with the tremolo and I have put links on my channel leading to his channel. Here is what he is doing:
www.youtube.com/watch?v=4P19ekxgZX8
He has a lot of views and a lot of subscribers.
Here is a playlist of my instruction videos:
www.youtube.com/playlist?list=PLJ1G4oHit4xhn6O-f4DBKy58fQ_ap6sFT
Somebody asked about how I play the tremolo. I made a video. More people asked more questions and more videos were made to answer those questions. My channel was driven by the questions people had.
Here are a few things I learned using the tools Youtube provides to creators and listening to subscribers comments.
Over half of my viewers are using cell phones or mobile devices. Visuals need to be large and simple to see on such a devices.
Most of the people looking for free harmonica instruction are male between the ages of 15 and 35.
Many speak English as a second language. Youtube is global. You need to keep terms simple.
Many of them want tabs.
Many have absolutely no musical background. Explain musical terms. Even simple ones like the word chord. Explain timing. Many don't know simple
time signatures or how to count them. I had to go back and make some simpler videos to insert into my series because I confused some folks moving
too fast and assuming some musical knowledge. Assume nothing.
Good luck. There is a lot of diatonic on Youtube already. But you may provide just the right knowledge that somebody needs.