Harmony is a fundamental characteristic of Western music—classical, popular and folk—from the Renaissance onwards. However, harmony is not a universal concept and is absent some non-Western musical styles.
The basic unit of harmony is the chord: three or more notes sounding together.
Chord
Role of Chords
Chords serve as a harmonic backdrop for melody. They support melody but also form an integral part of musical structure, style and expression. Chords are played softer than the melody, allowing melody to stand out.
Building Chords
Chords may be formed on any scale tone. Here's the scale studied previously:
Major Scale
When a chord is formed on a scale tone, this foundational tone is called the chord root. The letter name of the chord root is used to name the chord.
Chords | Each scale tone may be used to form the root of a chord.
The first chord above uses C as the root and is called a C chord. The lower case "m" used on some chords, e.g., Dm, is the abbreviation for minor: Dm = D minor chord. The abbreviation "dim" means diminished: Bdim = B diminished chord.
Roman Numerals
Chords may be referred to by scale degree numbers and written in Roman numerals. For example, "I" is the chord built on the first note of the scale, called the tonic, and "V" refers to the chord built on the fifth note of the scale, also known as the dominant. Roman numerals are mainly used for harmonic analysis.
Chord Symbols
In popular styles, chords are indicated with chord symbols (name of the chord), leaving voicing and rhythm up to performers. Chords may also be indicated with grids known as chord diagrams, depictions of where to place fingers for a particular chord on an 'ukulele or guitar. When a melody is written with chord symbols above the staff, it is called a lead sheet.
Lead Sheet | Melody with chord symbols and guitar chord diagrams
Sounding of chords one note at a time is called an arpeggio, i.e., broken chord:
Arpeggio
Arpeggiated chords are a common accompaniment for melodies.
Amazing Grace | Arpeggio accompaniment | Frary Ukulele Band
Baroque Guitar | Matteo Sellas, 1599–1654 | Popularization of chord capable instruments such as guitars and lutes coincided with early development of harmony in Europe. | Metropolitan Museum of Art
Harmony
The process of connecting and organizing chords is called harmony. When two or more chords are used in a sequence, it is called a chord progression.
Origins of Harmony
Initially, harmony was the haphazard result of combining of two or more melodic lines during Europe's late Middle Ages. By mid-seventeenth century, harmony was a formalized structure with composers writing melodies to fit chords.
How Does Harmony Work?
We'll look at how harmony works with a melody. Listen to the melody of Father, I Adore You played on the 'ukulele:
1. Father, I Adore You | Unaccompanied melody
The melody of Father, I Adore You sounds simple by itself. Next, I'll add harmony to illustrate how chords complement melody. I selected a four-chord progression that fits the melody: G C D7 G:
2. Four-Chord Progression | G C D7 G
These chords sound incomplete by themselves. However, this plain character is by design: harmony is purposed to frame and support a melody. In other words, harmony's job is to fill the background without upstaging the melody.
Harmonization
Finally, I'll put melody and harmony together. The process of combining melody and chords together is called harmonization. Listen to the harmonized version of Father I Adore You using the melody and chords heard above.
3. Father, I Adore You Harmonization | Frary Ukulele Band
When melody and harmony are played together, texture is full and complete sounding. The melody is the main focus whereas the chords provide a harmonic and rhythmic foundation. The process and roles you heard in Father, I Adore You are the essence of what harmony is and how it's used.
Kremona Mari Tenor 'Ukulele | Tenor 'ukulele used in the recording
More About Progressions
The principle behind chord progressions is simple: dissonant chords progress, i.e., move, to consonant chords. Why? The inherent instability of a dissonant chord stimulates progression to the next chord. In other words, it propels the dissonant chord forward to more stable and consonant sounding chords.
An extreme example of a dissonant chord may be heard if you drop your palms and forehead onto a piano keyboard. Here's the sound of a dissonant chord:
Dissonant Chord
Consonant chords are stable, thereby relaxing the listener:
Consonant Chord
Another example of a consonant chord may be heard when you start up a Macintosh computer or hear the HBO logo screen.
Tonic and Dominant Chords
In Father I Adore You, the third chord, D7, is unstable and causes the progression to gravitate back to the stable G chord. The G chord is built on the first note of the G major scale and, thus, is called the tonic chord. The D7 chord, built on the 5th note of the G major scale, is the dominant chord. The polarity between tonic and dominant is fundamental to Western harmony. Finally, the progression of dominant to tonic in the final two chords of Father I Adore You, D7 to G, creates a sense of repose known as a harmonic cadence.
Chords
Role of Chords
Harmony
More About Progressions
