musical saw 
noun
A saw, typically held between the knees and played with a bow like a cello, the note varying with the degree of bending of the blade.Thus the musical saw has an equal right to inclusion in the gallery as the cor anglais....
- I've come to know the sounds of her musical saw from a distance, and they fill me with dread.
- You don't often get to hear a didgeridoo, cello, organ and musical saw in the same piece of music, but if that intrigues you, here's your chance.