At the end of September I had the pleasure of a surprise visit from David Gildiner, Ryan Janzen and nessie the singing water snake. Developed by Steve Mann, the Hydraulophone is public art and the world's first water-based musical instrument. It is designed to challenge our conceptions of public art and people's interaction with it because it exists simultaneously as art and also as an interactive instrument anyone can play. It literally makes music from water. The keys of the piano are replaced with water jets. When you interact with the water flowing from its jets you create music - each jet is a different key - Hydraulikeys. Every other instrument uses only two of the three states of matter - gas and solids. This introduces the third state of matter to the orchestra - water.