Key Points

1. Harmony is the simultaneous sounding of two or more different tones. It can refer to the simultaneous intervals generated by polyphony, or to the chords (three or more tones sounded at the same time) or drone accompanying the melody.

2. Most of the world's harmonic systems are derived from the fundamental pitches of the overtone series.

3. Western harmonic practices, rooted in medieval European music, have developed into a highly influential system worldwide. This system is the basis of harmonic practices in Western classical, folk, and church musics, as well as jazz and popular music, including many non-western popular musics.

4. There are also harmonic practices that are not influenced by the Western system, including traditions from Bosnia and Zimbabwe.

Lesson Overview

Harmony refers to two or more different pitches sounded simultaneously. As other usages of the word suggest, such as "social harmony," music harmony usually involves a feeling of agreement, concord, or consonance. By producing music in harmony, people also enact an important social value.

Throughout the world, many people perceive the fundamental intervals of the overtone series-those with simple vibrational ratios-as being consonant. In Western terms, these intervals are fifths and thirds, and their inversions, fourths and sixths. Seconds and their inversions, sevenths, are usually heard as dissonant.

A simple kind of harmony is a drone: a constant, unchanging pitch or interval which provides a backdrop for melodies and rhythms. Drones may be long held tones, or they may be rhythmically articulated. They may be essential to the genre, as in North Indian classical music, or they may be considered optional, as in traditional Irish music.

The earliest evidence of codified harmonic practices comes from tenth-century Europe, when people began adding extra melodies to ornament the singing of traditional plainchant; this genre was called organum. Particularly at the Cathedral of Notre Dame in Paris, this practice became more and more elaborate through the twelfth century.

Genres of music that use two or more different melodies played at the same time is called polyphony (many sounds or many melodies). It is an important development in western music leading to innovations in how composers combine different tones at the same time, or what we call harmony.

By about the 1700s, developments in the western tonal system begin to shape modern practice. In other words, back then 12 tones were utilized in the the tonal system as they are today. Also, the frequencies assigned to those 12 tones or pitches basically remain the same today. What sounded consonant when combining tones back then, stays about the same today. The tonal system is also the basis for harmonic practices in today's Western folk and popular musics.

This western tonal system became the basis for harmonic usages in Western classical music through the nineteenth century. It was carried to other parts of the world through the hymns of missionaries and the musics of conquerors and colonists. Often this resulted in new hybrid musics, as European harmonies were combined with non-western practices. Some of the modern day descendants of this blending, such as salsa and reggae, have gained wide international audiences.

Similarly, African American musics are the result of a mixture of the European harmonic system and African musical practices. The fundamental chord progressions of blues became the harmonic basis of rhythm and blues and rock and roll. Jazz musicians developed complex variations on the Western system, and use their chord progressions for both composition and extended improvisation.

Harmony Is One of the Most Important Developments in Western Music

For our purposes, harmony in music happens when two or more different notes are sounded at the same time. Usually, the idea is that those notes are consonant or sound pleasing together. In western and European music that idea did not materialize until around the 9th and 10th Centuries. Before then, melodies were sung or performed in unison monophony. That means two or more instruments performing the same melody the same way at the same time. Around the 9th and 10th Centuries in Christian monasteries, boys began singing alongside men. Of course boys sang in higher voices than men. Hence, they started the melody on essentially a different note than the men. As you learned earlier, where there are two or different melodies sung at the same time, the practice is called polyphony. Remember, it also means that two or more different notes will overlap, which is also the definition of harmony. The practice of polyphonic singing essentially marks the beginning of the development of harmony in the west.

That ranks as one of the most important developments in the history of western music. Without harmony, we would not have had the western symphony orchestra, Mozart, Back, or Beethoven, let alone today's many forms of pop music that rely heavily on chordal harmony.

Below is an example of polyphonic chant. Note a dominant melody being sung in the foreground, whereas a choir sings long notes, in essence still a melody, but more in the background or behind the main melody.

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