I'm fortunate that I can play by ear (I can read music, but not very well). I can usually hear a song a couple of times and am able to play it. It's a blessing! I can remember songs that I heard in the sixties, and although I've never played them before, I can bumble my way through.

I'm a member of a local country music association and we meet once a month to play, sing & generally have fun.
The backing band is made up of whoever turns up on the day, and the members & guests are invited to get up & sing a couple of songs,
The only pre-requesite is they bring 3 copies of the chord charts of the songs they wish to perform.
Now, without sounding demoralising, most of the old country standards are only 3 or 4 chords, so not difficult, but I notice that the band, although they know the song very well, still keep there eyes on the chord charts.
Similarly, the performers have their words on a music stand, and their eyes are glued to them right throughout the song. They have maybe sung or played these songs a hundred times before, and they know them off by heart, but they still like the security of having the words/music in front of them.
They would be better off ignoring the words/music and interact with the audience instead.

Just my gripe. smile
I feel better now.

Cheers,
Keith