I think I got the idea correctly.... but didn't address it directly in my reply.

If you're going to write a new book or course on the topic, using this forum as a way to judge interest might not be the best idea. This is one of those things that you have to research and decide for yourself if there's even a market for the new product. Publishers may tell you it's not a good idea because there's already so many books on the market that cover this and it's not exactly an area of huge interest to most writers.

Can the market stand to have a new book/course on this? What new info does it bring to light? Will people be willing to part with the $30 or so it will cost? What if the publishers are not interested?

Of course, only you can decide to go ahead or not with this project. With the internet, there's no telling, it could very well be successful and another source of income.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.