A recording sample from an Art Harrison 126 tube theremin with adjunctive ductwork to add resonance and echo. The start is chaos and then settles down to the start pitch, followed by four verses of Away in a Manger. I had hoped that with four verses I might get one right. My budgie bird Mary flys into the room and crashes near the theremin at the end of the last verse.
The recording setup was plagued by an AC ground loop, amongst other problems.