It isn't posturing, some people's bodies are naturally more expressive than others, especially where music is concerned. My wife tells me that when I perform on clarinet I move a lot, but I never notice at the time. It would take an effort not to move and I couldn't focus on the music. Musicians like Heifetz, whose expressiveness is all in the fingers, are a rarity.

He doesn't move so much considering the physical and mental effort involved in playing this piece. You could force the clarinetist into a straight jacket with just his arms sticking out and then he would be still enough for you but the music would suffer. For me, having to stay close to a microphone when I'm playing is excruciating and I'm not into theatrical choreographed playing at all, it''s just natural to move when you play the clarinet. Maybe for other instruments it's different. Organists tend to keep their upper bodies still but then they're a bit like Irish dancers, it's all happening from the waist downwards.

That was a particularly postured effort. Thought that before reading your comment. (Unfortunately, though -- it's not just this piece.)

It is supposed to be at that tempo

It's q = 72, and they're quite exactly on the right tempo.

@@kaylaclarinetpiano try listen to John Mc'Caws version that Luis Rossi released on CD many years ago.

Fast, slow….so what?

@@ronaldreuben3278 It's a very lyrical concert if you dive into the music. It's not so much a technical showpiece with fireworks.