A most interesting thread, this.
I did play banjo or guitar as an accompanist, for some 10 years in a part-time, semi-professional way but gave up C. 1990s when the kids came along.
Lately I began to attend a local singing night which has regular members as well as a variety of casual attenders. I was sometimes asked to sing, as some people there remembered that I had been with a group, but singing had never been my forte, and also, I found that I was confined to singing the same three or four songs for which I have the lyrics.
I have had to work hard at this "new" skill and now, after some months, I have recovered my confidence and will sing "at the drop of a hat " for them.
I found that achievable by reverting to the repertoire of songs that we played with the group. I feel now, that I can attempt to learn some of the newer songs and my only obstacle is finding time and space for practise in a busy household. As one poster, almost, said, you have to be happy with your performance before inflicting it on others :-)