Thanks Gandalfe.
John, it was to show the instrument...
Well, I wouldn't really categorize this type of music. But in the art world it has a name. It's called Sound Art
http://en.wikipedia.org/wiki/Sound_art
It's not really a type of music, but a type of art that also uses sound.
Drew, your post is a little strange. You are basically suggesting she should do something different than what she did. Like someone posting about a clarinet and suggesting they play oboe for example. Obviously your idea can work in general, like someone posting about a clarinet, and in general, playing oboe might also be a good idea.
This sculpture was specifically made from this iron chimney. It was specifically made for the purpose of playing it mostly with bows. It was specifically made for the purpose that she will play it. The purpose of this sculpture is not to stand there and have everyone play it with their hands. Though people can do that if they want. However, after this concert, a lot of adults and children did play it, with the bows and with their hands. An instrument made from a different material, played without bows, would sound different and is not what she wanted to do in this case. She wants the sounds she got from these materials and type of playing.
Here is a photo of her Stringed Tree
http://farm3.staticflickr.com/2277/5796078404_5138097541_b.jpg
This is an olive tree with strings stretched on it. Since there is no resonance chamber they put pickups for each string and used amplification.
Here is a partial video of her first Stringed instrument
http://youtu.be/DEEnfYVatsk
It has very long strings stretched around a room and uses a long steel pipe and a couple of cellos as soul and resonance chambers.