Musical Science - Year 5

I was a little confused when I saw a line of 6 wine bottles on a table in Ms Kris' classroom.  When I went to investigate I discovered the children had been investigating how the amount of water in the bottle effected the note produced when the bottle was tapped with a ruler.  Having established the relationship between the amount of water and the note, the children worked out the musical scale and proceeded to play...well, have a listen, can you tell me what the tune is?
Leave me a comment.