In this video, Brett Youens describes the logic behind the system of overtones on valved brass instruments, with the tuba used as an example. www.geocities.com (Transcript) Hi. Let’s talk a little more about valved brass instruments and how they work. As you know by now this is a tuba, but could just as well be a trumpet, or a euphonium, or a French horn, or a flugelhorn. They all work on the same principles. The principle we want to talk about today is “overtones”. Overtones are all the notes that you can produce on your instrument without the usage of the valves. So let’s say you play a trumpet in C. What does that mean? That means, the lowest note you can produce on your instrument — without valves — is a C. That’s called the fundamental. But you can, of course, produce many other notes above that, and those are called overtones. So we have a fundamental and many, many overtones. Let’s say you play Euphonium in Bb. That means the fundamental is a Bb — that’s the lowest note you can play without the usage of the valves — and then you have many other overtones above that. One thing to know about the overtones — and we won’t get into the mathematics today — but one thing to know about the overtones is that they get closer and closer to each other as we go higher and higher up. So if the lowest note is here, and the next note is here, then the next note after that might be here, and the next one would be, maybe, here, the next one here, and the next one here, and at …