In this video, Brett Youens describes the two principles on which all valved brass instruments work, with the tuba used as an example. www.geocities.com (Transcript) Hi. Let’s look at brass instruments with valves and how they work. I have a tuba here; it could just as easily be a trumpet, or a French horn, or a flugelhorn, or a euphonium; they all work on the same principle. If I blow into the mouthpiece, then the air travels this path here, and comes out of the bell. Now, if we think about a trumpet, we’ll notice the first principle of the two principles we’ll need to know about how brass instruments work. A trumpet has a very short pathway for the air to flow through, and a tuba has a very long pathway. Trumpets produce very high notes, and tubas produce very low notes. So: The longer the pathway, the lower the note. The longer, the lower. So, if I want to produce a different note, then I’ll need to lengthen my tuba. But, of course, I don’t have time while I’m playing to get out a hammer and a nail and maybe some sort of smelting machine and lengthen my tuba. That’s what the valves are for. By depressing a valve, you make sure that the air takes a detour, thereby lengthening the tuba. So if I press this first valve here, you’ll see that the air takes an extra path. If I press the second — this little baby valve here — then it takes a detour of a shorter length. And if I press the third valve, then it’s this long, winding, granddaddy-of-them-all valve, right? So you …
