Found a piece of square aluminum tubing lying around. It already had holes in it. It needed to be a whistle.
Can a whistle be used in place of a trumpet mouthpiece? …no.
A pocket trumpet with a clarinet mouthpiece and a reed made out of a metrocard. Probably would be played better by anyone who knew how to play a trumpet or a clarinet.
I had a short time to make something with the Disklaviers before it was time to put them away.