The Perfect Fifth
first, let's focus on our new interval. The perfect fifth. Now we looked at our first interval on the previous unit and that was the octave right. That was Ah, eight white notes up, um eight in key notes up as we'll soon learn. The perfect fifth is ah, five notes up. Now don't let that word perfect throw you. That's kind of a just a terminology thing. We'll talk that will make more sense later when we talk about major and minor chords. But for now, let's just think of it as the fifth, Okay, so to find it Ah, let's start on the sea. So here's a C, and I'm gonna count five white notes up. So it's G. So the interval of a perfect fifth starting on C gets us to a G. So in other words, G is 1/5 higher, then see So ah, why do we care about the perfect fifth? Ah, when it comes to what I used, the lingo I used in the previous lesson was, you know, kind of like safe and dangerous things you can do. Ah, the active is super safe. If you're just working with octaves. It's gonna be pretty tricky to...
make something sound bad. Ah, the fifth is the second most safe, Uh, interval. You can make the fifth. If you just throw fists on everything, it's not guaranteed that it's going to sound great. Um, it's gonna have a particular sound, but ah, the fifth itself is pretty safe to use. So if you want toe, add a note to a melody that's gonna kind of beef it up and make it sound a little thicker. Ah, the fifth is a good note to you. So count up. Five notes Ah, of the key and you'll get there. Now there's a reason that we like the perfect fifth. Remember, we talked last time about when we're talking about octaves. We talked about the 1 to 2 ratio. You know, looking at the wave forms, the fifth has a 2 to 3 ratio. So for every to of our root note, we're going to call this a root note. Ah, we have three of the fifth above it wave forms. So all that really means if you're not following this stuff about weight forms, all that really means is that the wave forms fit together relatively nicely, and when that happens, we generate a sound that we tend to like. That tends to be a continent sound, we would say, as opposed to a dissonant sound. But let's take Let's take this analogy of or not analogy, this idea of the wave forms one step further to really understand it, because I want to look at how the fifth works when were dialing in a synthesizer, right? This is something that in the traditional music theory class you would never ever do talk about, like, you know, the specific frequencies of pitches. But when it comes a synthesis, we need to know this stuff. So ah, the perfect fifth is a to three ratio. What that means is that, for example, if we played our if, if this note our lower note, let's call that the fundamental or the root. Both those words can apply. The fundamental tends to me is more of a synthesis. Term route is more of a music theory term, but essentially meaning the same thing in this context. Ah, if that is hertz, then the fifth is going to be 1000 times 2/ or 1.5. So it's gonna be 1500 hertz that's gonna get us to, ah, fifth above the route. So let's look at how that works in a synthesizer. Okay, so I've loaded up an operator here. This is just a synthesizer in able to live. And I have made a MIDI clip that's just gonna play a note over and over it. Over. Right. Kind of. Sounds like your alarm going off. Um okay, So here's what I've done here is I've set this first oscillator. I've turned all the other oscillators off, so I just have one oscillator here, and I've said it to fixed mode, which means it's ignoring this pitch, and it's just kind of using that rhythm. And I've said it to one kilohertz, 1000 hertz. Okay, so I'm gonna add 1/5. On top of that, I'm gonna add another oscillator and turn it up, and I'm gonna add set this 1 to or 1.5 kilohertz. There we go. So here's the note without the fifth. And let's add the fifth in that is the sound of Ah, fifth on another reason we care about fifth is that we need them to make cords. Eso fifth become very important once we start assembling cords, which we really only need one more interval to start putting together cords.