[BLANK_AUDIO] In the last section, we talked a lot about the dominant triad and I talked a lot about the tonic triad, but actually as we talked about in week one, we can build a triad on any note within the scale and that's exactly what we're just going to do now. >> Yep, we're going to start with chord scale degree one. going to go up through all the scale degrees one, two, three, four, five, six, seven, one and we're going to build a triad on each scale degree. Now, just to be clear in how we're, how we're, we're notating these things for for, for, for differentiation we're using numbers for scale degree one, two, three, four, five, six, seven. When we build triads on each of those scale degrees, that triad is also chord one or chord five or chord four. We use Roman numerals when we, when we're talking about chord or triad numbers instead of normal numbers. >> Okay, so if we take C as our tonic in this case. We're going to build a triad on c, it's the first degree of the scale, and as Nicki said, we're going to call that chord one. Now on a major key, let's hear that again. We've got a major chord. Okay, let's go in to chord two. Chord two in the major key is minor, chord three is minor. Chord four is major. Chord five is major. Chord six is minor and chord seven is the one that was different. This is a diminished triad. Just to recap, between the first and the fifth, we've actually got a diminished fifth, not [UNKNOWN] perfect fifth as we have with the others. >> This would be a perfect fifth. This is slightly smaller, so we get a diminished fifth and in between we've got minor third from the first to the third. So, a diminished fifth and a minor third gives us a diminished triad . Chord seven is a diminished triad. >> Now, what's important to spot here as we go up the major scale is that we've got yet another pattern emerging in music theory. You remember that our major scale always has the pattern of tone, tone, semi-tone, tone, tone, tone, semi-tone intervals as we ascend the scale degree numbers. When we build a triad on every single, every single scale degree, traveling up the octave, we get that pattern of major, minor, minor, major, major, minor, diminished. That pattern stays the same, whichever [major] key you're playing in. Chord five is always major, chord two is always minor. >> So we can take any note and build a triad on it. But actually, it seems that when we look at music, and when we analyse pieces of music, there are some chords that get more use, some chords are used more often than others. >> We saw with Twinkle, Twinkle, with our little example, it was chord one and chord five, it was the tonic and the dominant triads that were really important structurally. In common practice music theory, chords one, five, and also chord four are the three sort of, most important structural building blocks. The subdominant, that's chord four, often appears before chord five and it sort of extends the whole structure that we've described with those perfect and imperfect cadences. >> But it's not just in big pieces of, of work from the common practice era that we see this. In fact, any diatonic melody, we can take and harmonize it with chords one, chords four or chord five. Since every single scale degree actually occurs in chord one, four or five, we can use these chords in conjunction with melodies built from this pool of notes. >> There's a lot more to say and we will go on soon, but first we have to carry on with our triad building exercise. [BLANK_AUDIO] >> Okay. So now we've seen the patterns that come out through triads built in a major scale. But what happens when we do this with a minor scale? >> Well, as you've predicted, based on what you know from the major scale, we're getting a whole new set of internal regular patterns emerging when we go through. The triads are built on each degree of a minor scale. >> We're going to use A minor this time, so, rather the c major, we're shifting to its equivalent minor. Starting with chord one. >> So chord one in A minor. You've guessed that is a minor, so that's a minor chord, on chord one. If we move up to chord two, we get a diminished triad. So it's like, it's like the seventh chord from a major scale, it's got that same [SOUND] diminished quality. >> Okay, then if we move on to chord three, we get something interesting happening here, because we're in our minor key. Now you'll remember from week two we talked about different types of minors. We were looking at this just now, we're going to look at the harmonic minor, and that gives us a new chord on chord three that we've not discussed yet. So we've got a major third, but if you look at the distance between the root of the cord, and the fifth. We've actually got 8 semitones now, which is one semitone more than the perfect fifth that we've already talked about. This is called an augmented fifth. So a chord that has a major third and an augmented fifth, we're going to call an augmented triad. >> And you don't realize that this is happening because chord three has the scale degrees three and five and seven in it. And you'll remember that what characterized the harmonic minor scale was it had a sharpened seventh. >> [SOUND] Okay, moving on to chord four. We've got a minor triad. And then going onto chord five, we've got a major triad, again encompassing the G sharp that was important. We now have our major triad. We move onto chord six, we've got a major triad. [SOUND] And then we go to seven. We're back to another example of a diminished triad. [SOUND] and back to the tonic again. >> Okay, so the properties that we get from the triads that we're building in the harmonic minor scale give us a really distinctive set of of distinctive set of, of patterns, of triads that emerge. We've got a mix of diminished, we've now got augmented and we've also got that major fifth happening on, on, on the when we buildup from the, from the fifth degree of the scale because we've got that leading note because we've got that sharpened seventh. So, it's really unambiguous. So, moving around in different keys, that pattern of triads would emerge from any key notes using a harmonic minor scale. [BLANK_AUDIO]
