I've found moving around on stage to be very
distracting for me. I know that it is much easier for
me to drop the ego when I have my focus. That usually
means I am not moving around.
My wife is a successful voiceover actress and producer (director). Actors
LOVE being directed by her. She constantly counsels that you should
concentrate all your energy into the mic, and not gesticulate wildly, or
move much at all, when recording, and this is in fact the generally
accepted practice in VO in LA.
She is talking about a recording situation. There are over a million good
reasons to map this to harmonica recording technique, too.
However, when you're on stage you should be yourself. That means that if
you naturally move around alot, then move around alot. If you don't
don't. Generally, strenuous motion will only look silly and break your
concentration if you have to think about it when you do it. Stillness in a
performing musician is a very compelling spectacle if it's real. Bluegrass
cats and bebop musicians don't even move a muscle in their face. The best
of those players look like statues when they're working.
Rock guitarists who try to act out every note with their bodies and their
faces generally look ridiculous, but their audiences often love that
stuff. (To me they look like air guitarists with extra hardware.)
And, well, Howlin' Wolf performed with every muscle in his body. I saw him
do the stuff he could still do in the early 70's, and it was a fabulous
spectacle. We've all heard stories about how in his prime he'd play harp
with one hand and climb the stage curtain with the other. And he got to be
Howlin' Wolf.
Back when I performed with bands, (and we had steam powered amplifiers and
we stopped our cars with our feet), I was always told I danced around when
soloing, but I wasn't really conscious of it.
Nobody ever threw a bottle at me, even though I mostly worked without
chicken wire.
So my vote is Be Yourself, and do what you do naturally, as long as the
audience doesn't kick up a fuss or walk out.