The cool thing about it is the “sustain”. Like violin, or wind instrument you can sustain a note pitch until you run out of air or until you have to return pull the bow. On the glass harmonica it sustains as long as you have your fingers on it. Now this particular detail is important. Because even on a plucked guitar you have to use electronics to do that. Analog is better if you can pull it off.
And that is the thought behind this Tub Cello. With a bow I will have the sustain. And with one string being tensioned at will I can seamlessly “bend” from one note to the next and beyond to the next and beyond to the next. As I sustain with the bow. No string changes or fretting needed.
I can see it being a great lead instrument if designed and pitched correctly...