What's going on here, I can only guess, but here's what you're about to see: In the video below, the great musician Glenn Gould, supreme interpreter of Bach, is sitting at his living room piano on a low, low chair, his nose close to the keys. He's at his Canadian country house in his bathrobe.
Through the window, you catch snatches of his back yard. It's a windy day and he's got a coffee cup sitting on the piano top. He's working on a Bach partita, not just playing it, but singing along in his swinging baritone. As he plays, he gets so totally, totally lost in the music that suddenly (1:57 from the top), smack in the middle of a passage, with no warning, for no apparent reason, his left hand flips up, touches his head; he stands up, and walks in what looks like a trance to the window. There's an eerie silence. Then, in the quiet, you hear the Bach leaking out of him. He's still playing it, but in his head, he's scatting the beats. Then he turns, wanders back, sits down, and his fingers pick up right where his voice left off, but now with new energy, like he's found a switch and switched it.
What just happened? I'm not sure. But I think this is a rare vision of what it's like to be so in your head you leave your body, or at least the moving parts of your body, totally behind.
Thank You, Poetessa.