So, in Lesson 2, we're going to talk more about the chromatic scale and, for better or for worse, we're gonna introduce some more musical terminology. Again, not in detail, but we need to know at least some musical terminology, and the terminology of the chromatic scale is crucial. So here is the chromatic scale. There are 12 intervals and 13 notes. This is a confusion that I'll probably misspeak at some times, and you'll notice it in different things that you read. There are 12 intervals in the scale, but 13 notes, and so sometimes it's called a 12 note scale. That's a little confusing, but the basic idea is 12 intervals and 13 notes. These intervals all have a name and they are two tones played together. So unison for example, and formally it's referred to as perfect unison, is playing the same note together. So if you're talking about a piano you can't really play the same note with the same note on a piano you need two pianos, but the same note on two pianos is unison. A minor second is the next note up in the chromatic scale. These intervals are all called semi tones, we'll come back to that in a minute. The third interval the third scale degree is called the Major Second. Next one, the Minor Third, and so on through this list of 12 intervals. They all have names, and those names we'll use from time to time to indicate a musical dyad, two notes played together. A note that's called the tonic note, we'll come back and talk about that a good deal. And the other note played with it, a higher note, that defines the interval, the frequency distance between the tonic note, which begins the scale, and any one of these notes in a sequence that covers the octave. Again, the octave being a doubling of the fundamental frequency, from the note that begins at the tonic note to a note that has a fundamental frequency twice the fundamental of the starting tonic note. These are the abbreviations, we'll sometimes be using these, and I'm going to leave out these other two columns. We'll come back and talk about tuning systems, and they're obviously critically important. How is it that you define the distance exactly between any one of these intervals that are dividing up the octave? And you'll see that's been a huge problem over literally millennia as people have debated what's the best way to divide the octave into semi-tones? What's the definition of a semi-tone? What's the unit between each of these intervals? And as we'll see, that remains a complicated issue. So there are three tuning systems that we're gonna be talking about, but for the moment, we'll let those go. Those three, just to give you a sense of what's coming, are equal temperament, Pythagorean tuning, and just-intonation tuning. I'll just mention here just intonation tuning because just intonation is tuning, well they're all in a sense tuning systems that deal with ratios, so the ratios that are involved in the two notes in the Chromatic scale. For unison of course it's one to one. For the octave it's two to one, that's what I said, a doubling of the fundamental frequency. But each of these other intervals has a frequency ratio between the tonic and the higher note that's being played along with it, the dyad. Let me just write that down, because we're gonna be using that term. Dyad simply means the simplest possible chord that you can imagine, playing two notes together. And, playing two notes together is the essence of the chromatic scale, the 12 notes of the chromatic scale. And again, just to come back and make the point because it's an important one, is the semitone. What's the proper definition of the interval that's more or less the same between each of these 12 intervals of the chromatic scale? Each semitone is approximately, depending on the tuning system that you are using, a 6% increment of the frequency of the tonic. The octave is a doubling of the frequency, a 100% increment. A 6% increment is approximately, again depending on the tuning system, for the distance between each of these 12 intervals in the chromatic scale. This is of course, a piano keyboard just to indicate how these notes play out on a keyboard for those of you who are familiar with it. The abbreviations are put in here, unison, the octave and all of the notes in between with their abbreviations. On a piano keyboard of course, there are semitone differences. Those of you who are players will know semitone being indicated by movement to an adjacent key from, be it a movement from white key to white key or white key to black key. The piano has empirically evolved so that the semitones are expressed in the movement to the next key on the keyboard. That's a semitone, and here's the layout of these terms in the chromatic scale illustrated on the keyboard for those of you who are familiar with it. So let's listen to the chromatic scale played by Ruby as just an auditory example of what the scale really sounds like. [MUSIC]
