This video was taken about 1975, so I apologize for the video quality. But the instrument - the Throne - is quite unusual: It's a slide guitar, with a controlled feed-back loop, creating long sustaining cosmic drones.
If you're listening with tiny computer speakers, I recommend turning down the volume, so the loud bass does not distort. The paintings are by Gilbert Williams:
The sounds of this instrument are featured in my "Timeless Sound" cd.