This is the idea that folks have, and they want/need/seek help with it. Sometimes they find their way to my Alexander Technique class.
We find tension in the neck or shoulders or back in response to the idea of singing or playing. Sometimes there's a tension that pulls one's body up off the chair. Some have a fearful response to the idea of playing in front of someone else.
As an Alexander teacher, I place my relaxed and open hand on the back of my students' neck or shoulders or back in a way that demonstrates how they can relax, too.
And we couple that relaxation with ideas: spatial ideas. The space between head and torso, the space between the shoulders. And grounding: relaxing feet on the ground, bottom on the chair.
Your homework: take just one idea, a little glance of a thought, that you can think in place of the usual worries, that lets you move more freely.
David's Musicians' classes-"Play Well, Hurt Less"
