seeing as its christmas ( whistle making advice needed )

i’ve decided I need a new whistle - we’ll ignore the sweetone high C i bought yesterday…

so last night i browsed a few online stores and found out that i’m poorer than a church mouse :frowning:

so a few whiskies later i came to the conclusion that i’m gonna have to make my own.

so down to the local hardware store today to buy some piping… i bought a few different sizes ( diameter ) and was on my way out when i spotted a square pipe…

so to the point - i’m wanting to try and make a low d out of the square pipe HELP!!!