[BLANK_AUDIO] In music, we find that certain patterns of chords, what we call chord progressions, recur frequently particularly at cadences. And we remind ourselves, of course, of the commonest cadence, Ic V I. [MUSIC] >> Which sometimes, is, enhanced by, a dominant seventh, on the the second last chord. So we hear this. [MUSIC] >> So a seventh, is added to the dominant chord, which serves to pull the music strongly towards the tonic, so it's a very strong progression and gives a pleasing finality to the cadence. You find in lots of music, for example the well known carol, Hark the Herald Angel sing goes like this [MUSIC] >> Or Happy Birthday To You. It goes like this. [MUSIC] And that's possibly the commonest of the cords progressions and cadences. Another cadential progression which we often find in, involves a different cord in the third to last position instead of the one C, we find two B and often with a seventh added chord. Let's stick to G-Major. There G Major. [MUSIC] Chord two. [MUSIC] The supertonic sounds like that. We add a seventh to it. [MUSIC] And then we put that in first inversion. So, we rearrange the notes in this order. [MUSIC]. And that's our third to last chord. [MUSIC] I'll just play that one once again. [MUSIC] In addition to these and other cadential progressions, are recurrent patterns of chords. We find chord sequences. The most common of these sequences is called the Circle of Fifths, which I think has already been mentioned. And this is a very important particular pattern. And it's found in 18th century music, by composers like Vivaldi, writing in early 18th century Venice, but also in later music of all sorts. The circle of fifths is so called because of the pattern of notes in the bass going like this from C to F, B to E, A to D, G to C, so you're going down fifths. [MUSIC] And if you put root position chords on top of that in the context of the key of C, it would sound like this. [MUSIC] [I'll play that again. [MUSIC] Here we are in, the same thing in G, circle of fifths in G, all root position chords. [MUSIC] Now let's here it with some real music. I mentioned the composer Vivaldi. Well, here's an example of a short piece by Vivaldi from his Concerto Grosso Opus 3. And he uses a circle of fifths, and it sounds like this. [MUSIC] And here's the music again. [MUSIC] You find exactly the same pattern of chords in the popular song, Autumn Leaves. Again, all the chords are in root position. This time, we're in G-Minor. And it goes like this. [MUSIC] Here's the circle. [MUSIC] So far the circle of fifths we've had have been with chords in the root position. But the circle of fifths also works with some of the cords in first inversion. Here's G-Major. [MUSIC] G-Major again. [MUSIC] You don't see the pattern of fifths in the bass because some of the chords are in the different inversion because the second fourth and sixth chords are all first inversion. But it's the same chords so instead of, [MUSIC] We have [MUSIC] And again, I'll play the whole thing. [MUSIC] And finally, the circle of fifths is sometimes used to modulate to a different key. Depending on how you arrange things, you can actually use the circle of fifths to change key. So for example, if we're in C-Major. [MUSIC] And we want to go to A-Minor, we might do this. [MUSIC] The all important G-Sharp,. [MUSIC] Which is the leading note of A-Minor, pulls us towards A-Minor but we have the circle there in the bass, once again C-Major to A-Minor [MUSIC] >> Or, we might want to go to G-Major. So, if we start again in C. [MUSIC] The important thing there, is that the first fifth is not perfect. It doesn't go F, it doesn't go C, F. It goes C, F Sharp, and that pulls around to G. So, here we are, again. C Major to G Major. [MUSIC] [BLANK_AUDIO]
