6. Harmony

Most simply put, harmony is the way a melody is accompanied. It refers to the vertical aspect of music and is concerned with the different music sounds that occur in the same moment. Western music culture has developed a complex system to govern the simultaneous sounding of pitches. Some of its most complex harmonies appear in jazz, while other forms of popular music tend to have fewer and simpler harmonies.

We call the simultaneous sounding of three or more pitches a chord. Like intervals, chords can be consonant or dissonant. Consonant intervals and chords tend to sound sweet and pleasing to our ears. They also convey a sense of stability in the music. Dissonant intervals and chords tend to sound harsher to our ears, and often convey a sense of tension or instability. In general, dissonant intervals and chords tend to resolve to consonant intervals and chords. Seconds, sevenths, and tri-tones sound dissonant and resolve to consonance. While some of the most consonant intervals are unisons, octaves, thirds, sixths, fourths, and fifths. From the perspective of physics, consonant intervals and chords are simpler than dissonant intervals and chords. However, the fact that most individuals in the Western world hear consonance as sweet and dissonance as harsh probably has as much to do with our musical socialization as with the physical properties of sound.

Here are some examples of consonant and dissonant intervals:

Ex. 1.13: Consonance and dissonance

A triad is a chord that has three pitches. On top of its root pitch is stacked another pitch at an interval third higher. On top of that second pitch, another pitch is added, again an interval third higher. If you add a fourth pitch that is an interval third above the previous pitch, you create a seventh chord. You may be wondering why we call chords with three notes “triads” and notes with four chords “seventh chords.” Why not “fourth chords?” The reason has to do with the fact that the extra note is the “seventh” note in the scale from which the chord is derived. (We will get to scales shortly.) Seventh chords are dissonant chords. They are so common in jazz, however, that they do not always sound like they need to resolve to consonant chords, as one might expect. One also finds chords with other additional tones in jazz: for example, ninth chords, eleventh chords, and thirteenth chords. These chords are related by stacking additional thirds on top of the chord.

Key (sometimes called “tonality”) is closely related to both melody and harmony. The key of a song or composition refers to a collection of pitches that it uses. The most important pitch of a key is its tonic, that is, the note from which the other pitches are derived. For example, the key of C major has C as its tonic; the key of A minor has A as its tonic; and a blues in the key of G has G as its tonic. A key is governed by its scale. A scale is a series of pitches, ordered by the interval between its notes. There are a variety of types of scales. Every major scale, whether it is D major, C major, or G-sharp major, has pitches related by the same intervals in the same order. Likewise, the pitches of every minor scale comprise the same intervals in the same order. The same could be said for a variety of other scales that are found in jazz, rock, and popular music, including the blues scale and the pentatonic (5-note) scale.

Table 1.1: Different types of scales

Major and minor scales are most often found in Western music today. The difference of sound in the major scale as opposed to the minor scale is in the perception of the sound. Major sounds relatively bright and happy. “Happy birthday” and “Joy to the World” (the Christmas carol) are based on the major mode. Minor sounds relatively more subdued, sad, or melancholy. The Christmas carol “We Three Kings” is in the minor mode.

Listen to a C major scale.

Listen to a C (natural) minor scale.

Music comedian Bill Bailey demonstrates the sounds of different minor scales and how music compositions sound different when they are changed to a different mode (minor to major or major to minor).

Ex. 1.14: Bill Bailey

You might notice that the blues scale and the pentatonic scale, both starting on A in Table 1.1, are very similar. This reflects the origins of the blues in folk music, as much of the folk music around the world uses pentatonic scales. A blues scale is like a pentatonic scale with an added note. In this example, the added note is the D-sharp (a pitch that is a half-step higher than D or a half-step lower than E). This added note is often called the “blue note.” In a sense, blues notes are examples of accidentals. Accidentals are notes that are not normally found in a given key. For example, F-sharp and B-flat are accidentals in the key of C. Accidentals are sometimes called chromatic pitches: the word chromatic comes from the ancient Greek word meaning color, and accidentals and chromatic pitches add color and excitement to a composition.

Chords can be built on every pitch of a scale.

Table 1.2: Triads of C major

In the key of C major, the C major triad is called the tonic triad, I (Roman numeral 1), because it is built on the tonic (first note) of the key. Every other chord in C major tends to resolve to the tonic chord. The two next important chords are the F chord, which we call the IV chord or subdominant chord, and the G chord, which we call the V chord or dominant chord. Popular music also uses the VI chord a lot. The chords of a key usually progress in an orderly fashion. Certain chords tend to resolve to certain other chords. For example, the V chord normally resolves directly to the I chord. We call a series of chords a chord progression.

One of the most important chord progressions for jazz and rock is the blues progression. A standard blues progression starts with the tonic chord (I), moves to the subdominant chord (IV), and then returns to the tonic chord (I) before moving to the dominant chord (V) followed by the tonic chord (I). This often happens in the space of twelve bars or measures and thus this progression is sometimes called the twelve-bar blues. There are many variations of this basic structure. The dominant chord in bar 9 sometimes changes briefly to the subdominant chord before going back to the tonic chord in bar 11; and the ending chord of a twelve-bar progression might be a dominant chord when it is not yet the ending of the piece.

Table 1.3: Standard twelve-bar blues in the key of C

Chord progressions play a major role in structuring jazz, rock, and popular music, cueing the listener to beginnings, middles, and ends of phrases and the song as a whole. Chord progressions in particular, and harmony in general, may be the most challenging aspects of music for the beginners. Hearing chords and chord progressions requires that one recognize several music phenomena at the same time. Chords may change rapidly, and a listener has to be ready to move on to the next chord as the music progresses.

The best way to learn to hear harmonies is to start with simple examples and ask general questions. Listen to “Light My Fire” (1967) by The Doors. Can you hear the general difference between the verses (which use mostly minor chords) and the chorus (which uses mostly major chords)?

Ex. 1.15: “Light My Fire”, performed by The Doors