(Or anyway what I was talking about in this post.)
So, I play two instruments and sing. Sometimes, when I’m watching or listening to music, it sort of… connects with my muscle memories? So that I’m almost but not quite actually moving my hands as if I’m playing, or almostbutnotquite mouthing the words of the song. (Or, same thing re: the feeling-in-my-throat of singing, or the breathing and gestures I would use to cue someone.)
It’s just barely on the line between imagining doing something, and actually doing it. The kind of feeling you can also get from being about to do something and being startled or interrupted.
And sometimes it’s really nice to focus on and encourage those sensations. It’s a way of connecting with the music physically.
I don’t dance, because dancing implies doing something that’s visually interesting to other people, but “connecting with music physically” = a nice thing.