Okay. So I've been trying to make one of these for a long time. I keep failing. And I would buy one, but there was only one ever made, which is the picture. So, naturally I came to the skills of the freelancers! So, I would prefer it be made out of wood, there are many ways to make a whistle out of wood. Or PVC pipe. I've tried both but I just can't get the whistle sound. I need it to be fairly long, maybe 1 foot long with the slide all the way in. I need it go pretty low and pretty high. I also need the slide to have a finger ring that is 1 inch diameter, and I need the slide to be able to move with hardly any force. I do have one problem with the one in the picture: the slides can't be in two different positions. I need it to be able to play chords. That is required. I do have a notch system in my mind for how that would work, but I want to see what you can create. So, look at the picture and do some research on slide whistles, wooden whistles (or whatever you are making it out of), and just whistles in general. I can provide links to examples and tutorials if you need them.