Well, for me it was a long slow process of giving them valuable content for free on YouTube (in my case it’s trade tips on building fitted furniture). That built trust and appreciation to the point that some of my subscribers were asking me to set up a place where they could contribute!
That’s how it started for me. Then as I grew the buymeacoffee idea I slowly added more member-only content including a set of blueprints I knew my followers would find very valuable. From time to time I will briefly show this in public youtube videos and describe the other content available to members only.
I recently announced on youtube that I would be doing less content publicly on youtube and more for members only and in the last week and a half since then I have had almost 100 additional members sign up.
I think the ongoing process of relationship building with your audience is most important and for me tis has happened probably more on instagram than YouTube - I also share helpful content in instagram stories, and it is a more direct way for followers to engage with me. I think it is very important to treat every individual as valuable and to quickly respond to direct questions etc, always being as helpful as possible. That way you slowly but surely establish yourself as an authority but also as a decent sort of guy who they know, like and trust.
It may be different for your area of interest though - my content is more about teaching technical skills. Having said that, you mentioned guitar knowledge sharing. I suggest doing some of this for free on youtube so people can find out if they connect with your teaching style. Then they will want more.