Four-Note Chords

(entry for 9/13/2024)

In the last post we talked about three-note chords called triads. Now it’s time to talk about four-note chords and the related topic of four-part harmony.

If you’ve ever sung from a hymnal, or listened to a traditional mixed-voice choir, or played in a string quartet, you have already been exposed to the concept of four part harmony, whether you realized it or not. (‘Barber Shop’ Quartets sort of count too, but only sort of.)

Many musicians believe that the famous Baroque composer Johann Sebastian Bach invented four part harmony, mostly in his 371 vocal chorales. It’s true that he more or less perfected the idea, but he didn’t invent it. It had been around for at least two hundred years before he was born.

In the Middle Ages, most religious music had two parts: one for men and one for boys. This had sort of a bare-bones feel to it, as it consisted mostly of perfect fourths and fifths, with other intervals being studiously avoided whenever possible.

The idea of using major and minor thirds, instead of fourths and fifths, to make the music more ‘flavorful’ seems to have come from John Dunstaple, an English mathematician and composer. (Virtually the only thing we know about him, with any certainty, is that he died on Christmas Eve in the year 1453.) This notion was first employed in what we now call ‘polyphonic music.’ (Also known as contrapuntal music. There will be a later post on this subject.) However, within a hundred years or so, people began to pay more and more attention to how different groups of pitches sounded together when played or sung simultaneoulsy, and this in turn became the study of what we now call harmony. Of which Mr. Bach was indeed the first master.

By Bach’s time, the medieval practice of limiting vocal music to men and boys had ended, and women and girls were now welcomed into the world of religious singing. 

(They had aways been welcome in secular music, but that was mostly melodic and rhythmic, without in any way being truly harmonic.) Since female voices tended to fall into two distinct categores—high and low, called Soprano and Alto, and since male voices similarly divided into Tenor and Bass, it became quickly obvious that four-part harmony was the way to go. (A choir divided into these groups is therefore called an SATB choir, with the acronym representing the four voice ranges. This is an exception to the ‘bottoms up’ rule in music. In choral music the voices are listed from the top down.)

For nearly three years, Bach composed one thirty-minute cantata every week, of which the last movement was always a four-part SATB chorale. These were composed during the week, and performed the following Sunday by the choir of his Lutheran church in Leipzig, with Bach himself at the organ. There was usually a very small orchestra involved as well. (Sometimes the first movement was in chorale form also.) As far as we can reconstruct, there were 143 of these cantatas. (A few are, sadly, now lost.) It’s mind-blowing to think that he could have written down that many notes in the time available, let alone invented the music that the notes represented! I mean, he had to eat and sleep, too, right?

Along with another 228 chorales that were not part of the cantatas, these works have formed the basic inspiration for all other four-part harmony ever since.

A mentioned in the last post, since triads are the building blocks of harmony, and since triads have only three distinct pitches per chord, and since most harmony comes in four parts, it becomes necessary to duplicate one of the triad pitches to create the four voices. The duplicate pitch is usually the root, or the name-note of the triad. Occasionally it’s the fifth, that is, the top note of the triad when in closed root position. Since the third of the triad (the middle note in closed root position) is the pitch that determines whether the triad is major or minor, it is usually considered ‘bad form’ to double that note. It lends the chord too much ‘flavor,’ as though you poured a half a cup of vanilla into your pancake batter. (Though Mr. Bach himself ‘broke’ this ‘rule’ countless times in his hundreds of chorales.)

The problem of which note to ‘double’ goes away when there are four separate pitches in the chord. (I don’t know of a generic name for a four-note chord, similar to a three-note chord being called a ‘triad.’ Quadrapad? I do’t think so!)

As mentioned last post, chords in closed root position are built of thirds. It follows, then, that all you have to do to create a four-note chord is pop another third on top of the two that are already there. The result is called a ‘seven’ chord, because the distance from the bottom note, the root, up to the top note, is always some sort of seventh interval. (Three plus three plus three equals seven? Music is not math!)

For example, if you take a minor third, and create a minor triad (in closed root position) by placing a major third above the minor one, and then add another minor third on top of that, you have a minor seven chord. (A G-minor-seven chord, to be precise.)

Another example: If you take a major third, surmounted by a minor third, thereby creating a major triad, and now adding another major third above that, you have what is called a ‘major seven chord.’ (G-major-seven, in this case.)

This is rather dissonant, and is used mostly in jazz. But if you use a minor third on top of the major triad, instead of a major third, you now have created what is called a ‘dominant seven’ chord, and this, by the way, is by far the most common four-note chord of all. Here are three examples: one built on C, one on F, and one on D. (This one on D is in root position, like the first two, but open rather than closed, just to keep things interesting.)

Note that it is perfectly OK to leave the word ‘dominant’ out, and just say G-seven (or whatever letter it is), or even G7. If the seven chord is a major or minor seven you have to say so, but if it’s a dominant seven, you don’t. You can, but you don’t have to. Because they’re so common.

It’s almost impossible to play through any song, of any style, and not have at least one dominant seven chord somewhere in it, unless the song is very primitive indeed. Even something as simple as ‘Happy Birthday to You’ has at least two dominant seven chords in it, and you can add even more than that if you want to, without harming it any. (A dominant seven chord is usually built on the fifth note of a scale, by the way [like G in the C-major scale], but doesn’t have to be.)

Technically, any seven chord is a dissonance, even a dominant seven chord. But that one is so common, and our ears have become so used to it, that it doesn’t really feel like a dissonance any more. In fact there are a (very) few popular and/or folk songs that end on a dominant seven!

That’s it for this post. There are many other kinds of chords, besides the basic three- and four-note ones. We’ll save those for later. But before we go, I should probably add a note about my statement early on in this post about Barber Shop Quartets. Most songs done in that style are actually three-part harmony with added notes that have nothing to do with the basic chord construction. They’re ‘extra-flavor’ notes (like adding cinnamon to your pancake batter) that are unusual intervals away from the other notes in the chord, including seconds and fourths, and sometimes even sixths. This kind of sound is called ‘close-harmony,’ but has nothing to do with the open and closed structure of triads and other chords. Very confusing! But easy to listen to if you when well done. (And terrible if not!)

By the way, if you're keeping score, so to speak, and if you'd like a quick review quiz, what's that chord at the head of this post? It has four notes. Is it a four-note chord? Nope! Trick question. It's a D-minor triad with the root doubled, and in open position first inversion!

Sorry about that!

*

copyright ©2024, LegendKeeper LLC

*

To see other posts in Len’s Music Blog, please click HERE.

For Len’s Memory Blog, please click HERE.