[MUSIC] If you've ever played guitar around a campfire while accompanying folk songs, you understand what harmonic function is. You even know about harmonic hierarchy, believe it or not. Harmonic function and harmonic hierarchy help you decide which chords to strum. Let's talk about harmonic function first. Here's a familiar campfire song, Michael Row the Boat Ashore. [MUSIC] The melody is in C major, the tonic note of the scale its built form is C. [NOISE] And this chord, [MUSIC] Is called a C major chord and it's the most important chord in the key. We call it the tonic harmony, because the tonic pitch, [NOISE] is the lowest note. [SOUND] This chord sounds fine at the beginning and end. Here it is at the beginning. [MUSIC] And here it is at the end. [MUSIC] There are times in the middle of the tune, though, when staying on that C major chord doesn't work. Here's what it sounds like with a C chord all the way through. [MUSIC] Let's do that up to the point where the tonic harmony no longer works. [MUSIC] Notice that when I get to the syllable lu, [MUSIC] It's impossible to keep playing the C major chord, I have to play a different chord. The harmonic function has changed and the C major chord no longer fits. This chord works nicely, it has the correct function. I'm sure you heard this over powering need for a different chord. When I changed chords at this point, I was also changing harmonies. So let's try to define harmony. It's one of those terms that everybody knows but it's hard to define. In its simplest sense, harmony is created by chords being strung together. A chord is just multiple notes being played at the same time. So this is a chord [SOUND]. This is a chord [SOUND]. Even this is a chord [SOUND]. But it's not the kind of chord that we'll be talking about. Harmonizing a melody means adding chords to it. But for the tone of music we're talking about, not just any combination of notes and chords will do. Here's a somewhat ridiculous harmonization of Michael Row. [MUSIC] It's not impossible, all of those chords fit the key. But when they are strung together like that, they don't create a sense of harmony, they're just a bunch of chords strung together. Tonal music gets its sense of direction from the change of harmony. Which starts out stable, becomes unstable and then resolves back to stable at the end. Harmony, in a way, is like the plot of a short story. The scene is set, the characters are introduced, the conflict is created growing to a point of high tension, which is finally resolved. Harmonic function is what the chords do, what their role is in the harmonic plot of the tune. When I harmonized Michael Row the Boat Ashore, I really needed to use the tonic chord [SOUND] at the beginning [SOUND] and end. Total music starts and ends with a stable harmony. That is this chord, [MUSIC] Has a stable function, which we need to make the song feel like it has ended. So let's put the tonic harmonies at the beginning and end, and show it here. So it starts like this, [MUSIC] And it ends like this. [MUSIC] Stable at the beginning and the end. Working backwards from the final chord, the harmony on the second to last note, [SOUND] demands resolution, like the climax of a short story. We couldn't possibly end on this chord. [SOUND] It's the chord with the maximum tension, so here's how it ends. [MUSIC] And that absolutely has to go here. [MUSIC] This unstable chord is called the dominant. Although it can happen anywhere in a song or larger composition, it almost always happens at the very end as the second to last chord. Later we'll discuss why it's called the dominant and what notes it contains but for now, I want you just to experience the sound of it. So you get a chance here to identify tonic and dominant harmonies. I'll play four chords and they'll either be tonic or dominant, combinations of them. So this is a tonic. [NOISE] This is a dominant. [NOISE] If I move the notes around, [NOISE] it's still a dominant. Here's a tonic. I can move these around also, and it's still a tonic. So I'll play four chords like this, one. [MUSIC] So they were tonic, [MUSIC] Dominant. [MUSIC] Dominant. [MUSIC] And tonic. [MUSIC] So, you try the questions. When you're accompanying folk songs, there's one more chord, one more harmonic function that you might need to know. Unlike the tonic and dominant, this chord is not absolutely necessary for every song. The function of this chord is to connect the tonic to the dominant. Another way to hear it is as a point of harmonic change that implies more harmonic changes coming. This is the harmony that we had on the syllable lu. [MUSIC] When we were forced to leave the tonic harmony. The chord we land on is clearly different from the tonic but it doesn't demand resolution. In fact, we go back to the tonic almost like we're going to try one more time. [MUSIC] We didn't really feel a sense of resolution, we just felt a sense of starting over a little bit. This so-called predominant chord is just that, a cord that prepares the dominant. There are several similar chords that have this predominant harmonic function. Here's one more set of in video questions with more chord functions for you to identify. This time I will include all three functions tonic, predominant and dominant. So I might have a tonic [NOISE] and another tonic, [NOISE] followed by a predominant, [NOISE] followed by a dominant [NOISE]. Or I might start with a dominant [NOISE] and have another dominant [NOISE], followed by a tonic, [NOISE] and then a predominant [NOISE]. I want you to see if you can hear those three functions, the stable tonic function, the connecting predominant function, and the unstable dominant function. Here's what I talked about in this lecture. Notice that I am talking about harmonic function when I use the terms tonic, predominant and dominant. By the end of this course, we will also be using those terms to refer to specific chords. It can be confusing, but the difference between chord and harmony and harmonic function is important, particularly if you are accompanying folk songs around a camp fire. In the next lecture, we'll continue this discussion of cord versus harmony. We'll see how changing cords doesn't necessarily change the harmony. [MUSIC]
