Be fair, the boss is using a memory aid, like most people. The extension of the thread into this discussion refers to singing into a book, electronic aid, whatever, which rarely translates into projected entertainment. You, hopefully I and many of us can read, play AND think about the delivery. I reckon its that last bit that prevents would be decent players from progressing.

You and I hear a good friend of mine sing the same half dozen songs, every other week, eyes glued to the page. Has done for years and years and still sounds like someone playing publicly for the first time. He has to have his eyes glued to the page, including stopping to turn over. He enjoys playing but every bugger nips to the bar. If you removed his crutch, I guarantee he would improve immensley, which he would love dearly to do. He would be where he wants to be by now in the old style folk clubs.

I suppose its a bit like wearing headphones whilst listening to music and find yourself singing along. Ask anybody in the room, even if you happen to be Mario Lanza, whether your singing was nice to hear...