Music Theory: Harmony Part One (basics)
Welcome to the My Music Masterclass blog. My name is Nathan Towns and I am one of the administrators on this site. I am also a film composer and bona fide music theory nerd. I thought I might utilize this platform to share my theory knowledge with you. I like to consider myself quite knowledgeable in this field; nonetheless, I am human and might make a mistake or two somewhere along the line—with this in mind, if you spot any, let me know and I will correct myself. This will be an ongoing blog, and I hope to be able to discuss a range of different topics related to music theory. I’m going to start this first blog entry on harmony and how it is used differently in different musical styles.
I’m going to assume that you guys have a basic knowledge of harmony, but I’ll give a relatively short overview nonetheless. Harmony is the simultaneously sounding of three or more notes making up what are called chords. While there are an almost infinite way to combine all of the notes in western music into groups of three, by far the most common is the triad. A triad is, as its name implies, a chord built on thirds. The configuration of this is: root, third, and fifth—the third is a third above the root, and the fifth is a third above the third. Depending on the quality of these two third intervals, the quality of the triad changes. Below is a chart showing the different qualities of a triad you can have with the root note of C.
Note that the chart above lists these chords from left to right organized by the composition of each triad, not in any order of prevalence. Major and minor triads are by far more prevalent than the diminished or augmented variety.
As you can see, there are four different types of unique triads that one can create by stacking major thirds and minor thirds. Starting from the left:
• The first triad is called a diminished triad. It is so called because the fifth scale degree is lowered (or diminished) relative to a minor triad, and is made up of two minor thirds stacked upon one another.
• The next triad is called the minor triad—it is created by stacking a minor third plus a major third.
• After that, we have the major triad, which is created by stacking a major third plus a minor third.
• Finally we have the augmented triad, the least common of the triads, which is created by stacking two major thirds.
The vast majority of music is comprised of these four chords and I think it is interesting to note why this is so. In almost¹ all sounds that have a distinct pitch, there is an acoustic property that both gives it its specific timbre and also explains the prevalence of triadic—and even more specifically: major and minor—harmony. If you play a C on a piano, you aren’t only hearing that C but also a series of notes above it as illustrated in the chart below.
This is the harmonic (or overtone) series. You can see that, within the harmonic series, the first three note chord one can create moving from left to right (or bottom up) is the C major triad—made up of the second, third and fifth partials. Playing a chord made up of these three notes mimics the overtones present in the root and tends to “lock it in to place”, so to speak. This is the primary reason why major triads are the building block of western harmony.
While the harmonic building blocks of western harmony are the major and minor triads, the melodic building blocks of western harmony are the major scale and minor scales. The reason why these scales—and not a scale that more closely resembles the harmonic series—are so predominant in western music requires a somewhat more of an in-depth explanation, one which I will not get into for the time being.² Below is a chart that shows the major scale starting on C. The minor scale—more specifically the natural minor scale, which is the one which I will discuss in this particular blog—can be thought of as these same notes, but starting on A instead of C.³
The numbers above each of the notes in the scale correspond to the “scale degree” of each note. Each of these scale degrees has a unique melodic tendency, whether that be a feeling of resolution or a tendency to want to resolve to another note. Do note, however, that the eighth scale degree is merely the first an octave higher, and has the exact same tendencies.
•The first scale degree is called the tonic—it is the home base, so to speak, and has a strong feeling of resolution; the vast majority of literature in almost every conceivable musical genre ends on the tonic.
•The second scale degree is called the supertonic and has a strong tendency to resolve down a step to the tonic.
•The third scale degree is called the mediant and has a relatively weak sense of resolution due to its position as the third of the C major triad.
•The fourth scale degree is called the subdominant and, depending on the harmonization of the note, holds the tendency to want to resolve either down to the mediant or up a scale degree.
•The fifth scale degree is called the dominant and can either have—again depending upon the harmonization—a very weak sense of resolution or a strong tendency to want to resolve to the tonic scale degree
•The sixth scale degree is called the submediant and has a weak tendency to want to resolve down to the dominant.
•The seventh scale degree is called the leading tone and has a very strong tendency to want to resolve up to the tonic.
Obviously, music isn’t written in only one or the other of these dimensions—harmony or melody—but rather as a combination of these two. Because of this, triads can be built upon each of the different scale degrees. Below is a chart depicting the quality of each of these resultant chords.
The roman numerals under each chord depict the quality of each chord. Upper case numerals designate major triads, lower case designate minor triads and the lowercase with the “º” designates a diminished triad.
With these basics out of the way, I am going to delve into the harmonic language of several different musical styles and how they use these triads differently to create unique and exciting sounds. The following posts are going to explore: classical music (common practice), jazz music, popular music (rock’n’roll, et cetera) and film music.
¹ Some instruments, such as the marimbas, vibraphones and bells (especially carillons) have what are called “non-harmonic partials” which are not part of the overtone series. They still have other partials that are harmonic, which helps reinforce their sense of pitch; non-pitched percussion instruments tend to have many non-harmonic partials, and this is what tends to cloud their sense of pitch.
² Don’t worry, I will write a future blog post on that subject and will go into greater detail on scales in general but for now, for the sake of brevity, let us just accept that it is so.
³ The only difference in scale degrees between the major scale and the natural minor scale is the seventh scale degree: in natural minor, the seventh scale degree is known as the subtonic, and for our purposes, has the same tendencies as the leading tone.