Well, when I started to perform in public for the first time last year, I was told by a fellow musician that it sometimes helps him to close his eyes while he sings. It lets him concentrate on the song he is singing. So it helped me for a while, until I got comfortable singing in public. So I started to open my eyes to see the reaction on the audience I am playing. And it was interesting to see some audience members singing along, and expression on the people faces was priceless. Because they really like the song you'd play, and you had a great time playing that tune.

For me it's what you are comfortable with. Eyes closed or open. Me it is both. Like me not such a season veteran in the music world yet, I work at it, playing in public.

Anyway, that's my .02 cents worth.

Steven