Well, that head-back, eyes-closed thing is common with concert pianists (or used to be), and sometimes, anyway, comes from "communing" with the music. But the raised hand, leaning left and right, etc., is often showing off, which some feel is, indeed, "showmanship."

However, it is good to see people at least trying to do something to make their show into a show, even if it's artificial. I'm in a couple of bands, and mainly just play, but have been reminded by the leader of one of them that I should connect with the audience, not just concentrate on my left hand (playing fretless Minstrel banjo takes a bit of concentration, at times). So I've been improving that. When I do a solo show, I am much better at connecting with my listeners, though at times I close my eyes mid-song (the words are projected on my eyelids, of course), but in the band situation, I'm trying to connect with my band-mates (keeping one from speeding up and another from slowing down, for instance), so the audience has competition for my attention.

But, as someone upthread said, "Whatever works."

Bob Clayton