So now that we know what keys are and how keys work, let's go back to that problem we found when we were looking at the perfect fifth. And why that be toe f thing didn't work correctly. Okay, so let's go back to a key of C major. Okay, so here's a seat and let's just draw out. See? Major Whole step Will step, half step. Whole step. Whole step. Whole step half step. Okay, there's all my notes and see, Major. Now let's look at our fifth. Now remember to find 1/5 a perfect fifth. We count up five notes in the key 12345 So the fifth of C is cheap right now, that is assuming were in the key of the first note. And it just so happens that to count up 1/5 of all of these notes lands you on a perfect fifth except for this one. So what we need to do to really figure out what the fifth is is count up 1/5 in that key. So let's switch to a key of B major. So it's start on me and go whole step whole step half step, Whole step, Whole step whole step half step. Now I'm in the key of B major. Okay, so ...
if I kind of I end on f sharp. So the fifth of B is f sharp, But when we count up 1/5 of be in the key of C major, we end on F Natural. This is a thing you'll find, and it's unique to the seventh tone of the scale. Uh, if now that I'm in the key of B major, if I count up 1/5 from a sharp here, I'm gonna have the same problem because this is the seventh note of the scale. 123467 It's always gonna happen when you build 1/ on the seventh note of the scale. Just one of those weird things you have to build 1/5 from, uh, in the key of the fifth. So when we do it in B and we apply the key of B to making 1/5 it ends up on f sharp. But when we do it in the key of C and count all the way up to be, we end up our Sorry when we do it in the key of C and count from B toe F we end up with an F natural because of Sharp is not in the key of C right. The key of C is only white notes. So if Sharp doesn't exist, so the correct note that is a perfect fifth in the key of C isn't in there. So we end up with a note that is not perfect. And again, it's gonna happen in the seventh scale degree only. So I know that's a little confusing. When we start to build cords, you might see ah, how that comes up, Um, and the way that we deal with it. Um, the seventh tone of a scale is, generally speaking, the most dangerous, Um, in terms of working with it, either as a single note or as a cord. So we just have to watch out for that, um, and treated a little differently when we do use it. Just one of those things to keep in mind for now. Okay, One last thing about fifths. Why do we care about fifths again? Um, I want to remind you, uh, what I said at the beginning of this unit, which is that fifth have a very important role to play for a couple of reasons. One is that they usually sound good too. As that we need him to start building courts. Three is that they are the single most powerful note that leaves us back home now. What I mean by that is when I play the fifth note of a scale, it has a tendency to it. It has a tendency to make us want to feel the tonic. So this is a gesture. It is a a way to end a piece is to go five. One is something that people that write music have been doing for literally centuries. This is Ah Strauss all Sprock Zarathustra. This is a classical piece. But you've heard the opening of this piece in ah, many things you've heard it in. Ah, a lot of different movies. I think Elvis used to walk out on stage to this. Ah, you've heard this before, so let's just listen really quick and okay, So that opening gesture, let's figure out what we were hearing. There were this. So let's assume we're in the key of C um because we are, um I just happen to know, um, So the notes we heard for that opening gesture were see g 1/5 and then see another see. And then we heard and we landed on so we heard e d Sharp. So D sharps not in the key, but that's OK. We'll deal with that later. The main thing we heard was C E. C. So let's see what that sounds like in context, right? That's the main melody. So this pattern of siege is is just this very heroic sound that we like to use for stuff. One last thing is that whenever you look at a lot of different instruments not all instruments but like string instruments, like not guitars but violins and cello, Zand, villas and things like that those strings are tuned in fifths. So this is a note on this is their next open string. That's how there's strings are tuned by fifths. So of see, 1/5 higher is G G. 1/5 higher is de etcetera that actually tuned like that low one of violin is G de and then in a and then an e. So they're tuned in fifths like that. So this would be each open string of a violin, for example. Um, and the reason that they're tuned in fifths is because we just like, fifth so much that these instruments were built to be able to just be fifth machines. I mean, obviously, they could do way more than that, but, um, that sound of the big fifth is just built into a lot of instruments. So that's why the fifth is very important. Interval. Okay, let's move on and talk about Mawr intervals and our next big unit. We're gonna talk about more things about keys, and we're gonna focus on the third, which is a new interval for us. Um, and it's going to lead us to building our first chords, because once we have the third, we can put that together with, ah, fifth and then a root note, and we have cords, cord lift off. So let's dive into that next