The Nuts and Bolts of Music - Part Three: Harmony
n our first article dealing with the basic musical elements--rhythm, melody, harmony, form, dynamics and texture--we talked about what is probably the most instinctive or "primitive" element of all: rhythm. Our second article, Melody, was concerned with single notes that are strung together "horizontally", as it were, to make a purposeful line or tune; melody is, in fact, often called the horizontal element of music. In the present article we are concerned with notes that are placed together "vertically" in simultaneous groups, or chords, so that they sound together as a blend.
This article includes musical illustrations in MIDI sound; to hear them, click on each example separately as you come to it. The linked musical examples will open in a separate tab or window.
A chord is a group of three or more tones that make an acceptable combination when heard together, and right away we're getting into muddy water because the qualifier "acceptable" has a pesky habit of changing its meaning every time you consider the music of a different era or culture. Many chords that were used by Beethoven would have been utterly unacceptable to, say, a medieval monk, while the great German master himself would have been perplexed (though probably intrigued) by a lot of the chords invented by Debussy. Again, much traditional music of Africa and the Orient doesn't use chords in our sense of the term at all. So for this article we will talk mostly about the good old-fashioned "traditional" chords that we hear in Happy Birthday, The Star-Spangled Banner and the like.
Harmony is simply the mix of sound that is produced by the ongoing series of chords that make up a musical composition as it progresses. Harmony always refers to simultaneous sounds, while melody alludes to single tones that are successive. The chords which make up the beginning of America look and sound something like this [Ex. 1]:
What you're hearing is the harmony by itself, without the familiar melody on top. Using spatial metaphors to describe sound is always limited, but just from the arrangement of notes on the page it is easy to see why harmony is called the vertical element of music. Any composition that is more than just an unaccompanied melody will make a blend of sounds that are both simultaneous (vertical) and successive (horizontal)--melody and harmony working together throughout, like the interlocked alignment of the words in a crossword puzzle.
Very often harmony results
indirectly from the combining of separate melodies
That's right: Dixie and Yankee Doodle played together--who said the North and South couldn't get along?
The most commonly used scales are major [Ex. 4]:
. . . and minor, which is the same except that the third and sixth tones are lowered [Ex. 5]:
Example 4 is the scale of C Major, and note that the top and bottom tones (both C's) sound like arrival points, or "home". In fact, both scales (the other one is C Minor) have this characteristic, which is caused by the fact that the neighboring tones are not all the same distance apart. A scale provides the tones for the chords of a key in exactly the same way that the twenty-six letters of the alphabet provide the letters for all the tens of thousands of words in the English language. To be in a key, then, means to be in a scale, so if we were to play Happy Birthday in the key of C Major we would construct its chords from the tones of that scale [Ex. 6]:
.....and the final chord sounds like "home" because it's built on the tone that is the arrival point of the scale.
What would happen if we constructed the chords of Happy Birthday from the scale of C Minor? [Ex. 7]:
Maybe that's the way we feel like singing it when we get older! When you use a minor scale, you come out with a minor key.
Composers are not, of course, bound to use only the tones of the scale they happen to be in at the time. Other tones lie between the eight degrees of the regular scale and, though not a part of it, combine to provide a total of twelve different pitches available within the scale's range. These can be used in a great variety of ways, not only to add richness to or between the regular chords of the key, but to provide the material for the building of scales on other pitches as well, giving us a total of twelve major and twelve minor scales. Thus music can be composed in any of 24 different keys.