I am watching From Here to Eternity and Cliff is playing his bugle mouth piece. Can a person really do that? Will it sound like it does in the movie? Can you do the same thing with a trumpet mouth piece?
I don’t recall seeing it in that movie so I can’t say if the sound was accurate but you definitely can do that. The instrument is basically amplifying and modifying the sound made by the lips against the mouthpiece. You can also do it with a trumpet mouthpiece (I used to do it) but of course your notes are limited (like a bugle) because you don’t have the valves, which in a trumpet modify the pitch by changing the length of the tubing.
You can do it on any brass mouthpiece. If you spend any time around a band with horn players, you’ll see/hear plenty of people warming up by “buzzing” their mouthpiece. It’s the only way to get your face warmed up properly without having to actually blow into your horn.
In marching band in Ohio it’s a particularly prudent thing to do before going out on the field in the winter. If you can get your face muscles warmed up and your mouthpiece (a big hunk of solid metal) warm, you’re halfway to having a good sounding show.
No, you can play pretty much any note you like on a bare mouthpiece, and this is what I do for a minute or two while warming up. None of them will resonate appreciably though. The fixed length of the mouthpiece is irrelevant; you can’t produce a note that will resonate in such a short pipe in the first place, so you get a very thin unamplified tone no matter what note you’re hitting.
Brass players do it all the time. When I was still a band member in school, we’d always carry our mouthpieces around with us so we could “practice,” ie annoy others.