My grandfather used to pick a piece of paper, bend it in some way, and put it on his lips to blow and improvise on a song. It sounded quite cool. He used to call this "sordina" (mute, sourdine), that's the same he called an "instrument" (not really that, I guess) that I recently saw played at a small acoustic jazz gig in a bookstore here in Mexico (it looked a little bit like a homemade battered tin trumpet mouthpiece of sorts). But then I can't find anything on the internet with that name (or that resembles it). What's the name of that instrument/action/performance? Can anybody help?
Sounds like a form of Kazoo:
The term covers numerous different sorts of home-brew musical gadgets such as you describe - improvised instruments that make some sort of musical sound using the breath and voice with paper or cardboard, etc - even metal:
To answer the caption on your post that would be called a reed. When I was a kid and my parents used to take me to the flea market and they had these flat pieces of vinyl a circle cut in half with a piece of clear plastic in the center with a metal washer bent in half over the top of it and you can place it on your tongue and whistle really really loud. if you knew how to move your tongue you could make yourself sound like a bird.