Major Scale, Tonic Triad, Key Signatures

Hello there, I'm Dr. Katie Meyer. In this video, I'm going to teach you about the major scale, tonic triad, and major key signatures. What is a major scale? The major scale is made up of the main tones in a major key. It follows a pattern of whole and half steps. Whole-whole-half, whole, whole-whole-half. This asymmetrical layout gives each member of the scale a unique position, name, and syllable. For instance, here's the C major scale. It's called the C major scale because C is the bottom-most note of the scale, also known as scale degree 1. Looking at the keyboard above, you can see the pattern of whole and half steps used to create the C major scale. It sounds like this. A moment ago, I said that C was scale degree 1. But what is a scale degree? A scale degree is a specific member of a scale. Each scale degree has its own solfege syllable, do-re-mi-fa-sol-la-ti-do, its own number, 1 through 8, and 8 can also be 1, with the little caret above to indicate scale degree number, and its own name, tonic, supertonic, mediant, subdominant, dominant, submediant, leading tone, and tonic again. Let's look at an example of a scale used in popular music. This excerpt is from the chorus of The Beatles' I Wanna Hold Your Hand. Here, G is scale degree 1, and the melody goes in a descending scalar fashion all the way from 8 to 1. Have a listen. In addition to building a scale surrounding scale degree 1, we can also build a chord on scale degree 1, called the tonic triad. It's made up of scale degrees 1, 3, and 5. While the tonic triad is a chord, its tones also frame motion throughout the scale. Scale degrees 1, 3, and 5 are the most stable, often used as starting points and goals of motion, while the other scale degrees are active and unstable. Look for example in this Mozart overture. The tonic triad is D, F-sharp, and A, and it frames the motion through the first three measures. The motion between these stable points forms musical gestures. Have a listen. We can build a major scale on any tone, but we must adhere to the pattern of half and whole steps starting from scale degree 1. For example, if we used the note D to start a scale, using only the white notes of the piano, it would sound like this and have this step pattern. But, not quite what we're looking for. In order to make it a major scale, we must raise the 3rd and 7th scale degree by a half step and make it sound like this. Raising the tone by a half step uses the sharp sign. If we needed to lower the tone by a half step, we would need to use the flat sign. So, what are sharps and flats? These are signs that raise or lower a tone. Importantly, they also change the letter name, which is the name of the pitch regardless of its scale degree, and it will always include sharp or flat. So, for example, we have F, and if we add a sharp to it, we'll be calling it F sharp. And if we have a G, we add a flat to it, we'll call it G flat. So, knowing the names of sharps and flats, we can build scales on any pitch or any scale degree. However, it's kind of a pain to write out all the sharps or flats that we want to use in a major scale that isn't C major. So, we use a key signature as a form of shorthand. A key signature shows all the sharps or flats in the scale of a given key. Below is the order of sharps for sharp key signatures and flats for flat signatures. It will be very useful to memorize these orders. Here's a diagram we call the circle of fifths. It shows all the possible major keys and key signatures. We call it the circle of fifths because the number of sharps or flats matches the number of fifths, or spans of five scale degrees, above or below C. So, for example, starting at C and going clockwise, a sharp is added for each subsequent key signature going around to the right. And going counterclockwise, a flat is added for each subsequent key signature going to the left. Now, take note that there are three enharmonic key signatures, meaning the keys are played the same, but they have different names. So, C sharp and D flat, for example. If you memorize this circle of fifths, you can memorize all of the key signatures. In this lesson, we learned that the major scale follows a pattern of whole and half steps. Whole, whole, half. Whole. Whole, whole, half. The tonic triad is built on scale degrees 1, 3, and 5. Printed music uses key signatures to create major scale step patterns beginning on any tonic pitch. And, by investigating the sharps and flats, we can deduce the key signature, scale degree, and pitches of any major key. That's all for now. Thanks for watching!