Music harmony can be described in several ways. For a basic definition, harmony is simply two or more pitches played simultaneously. This is how basic chords are built. By combining multiple pitches, usually at least three, a chord is formed. There are a thousand different types of chord, even though many of these don’t appear in Western music.
Harmony is also defined as the counterpart to melody. For example, by adding a melodic line a major or minor third above the melody, a harmony is created. Whether the third is major or minor depends entirely on the scale used in the melody and chord progression. Using the wrong kind of third results in a musical clash, or dissonance.
Different kinds of harmonic structure result from using different intervals. The fifth is a commonly used harmonic device. This results from adding a note a fifth above the melody and is very universal. Most scales tones can be separated by a fifth, so there aren’t as many odd notes using this type of harmonic theory.
More complex harmonic structures require a greater knowledge of musical theory. Using the seventh is common to give the melody more of a blues or jazz feel. Jazz harmonies can often be quite complex, spanning the octaves to add ninths, 11ths or 13ths. These intervals can be hard to keep in tune when performed by vocalists, as the span between notes is great. Great vocal groups often use harmony to create chords with their voices.
One argument about harmony versus dissonance lies in the perspective of the listener. An extremely dissonant group of notes may sound absolutely beautiful to one set of ears, while sounding completely terrible to another. A lot of non-Western and avant-garde music uses the concept of dissonance to great effect. For example, a melody that begins with the C note may have C# an octave above it added. To certain listeners, this sounds absolutely frightful, while others sing its praises. Harmony is in the eye of the beholder.
Different harmonic ideas can be presented by using inversions. Inversions involve taking the lowest tone of a chord and transposing it up an octave. For example, a C major chord consists of the notes C, E and G. Taking the lowest tone, the C, and moving it up an octave creates the same chord with the notes E, G and C. This gives a different harmonic feel to the chord, allowing different notes to stick out more than others. This technique is very useful when devising harmonic movements.
Harmony takes the task of building up the sonic structure of the song so it is fuller-sounding. The harmony compliments the melody and adds counter-points to create different “feels” to the resulting total compilation. (Think of it like the walls of your house) In staying withe the whole diva theme, harmony steps in as the backing vocals, the choir, the wall of sound that helps lift the lead vocals.
With harmony, we start getting into the discussion of chords, that is, the blending of notes to create a particular sound. Different types of music accomplish creating harmony in different ways. For example, how do you think an orchestra creates chords? It’s actually a bit different than how we guitarists create chords.
You see, guitar is one of the few musical instruments with the capability of playing chords. For most instruments in an orchestra, they play one note at a time.
So to accomplish chords, the orchestra (or band) might have multiple instances of an instrument, each playing a different different complementary note that when combined creates the sound of the chords. Whether it’s the string, brass or woodwind section, the individual musicians would have sheet music customized for the part they are playing.
When you think about the amount of work that would take a composer to imagine and write all the different instrument parts, you begin to have a new appreciation for artists like Mozart, Beethoven and Bach. To be able to conceptualize and then create an entire piece, write it all out and then direct the musicians performing the piece just seems like a monumental task.
Another benefit to creating the harmony with chords is the melody can ride on top of the sound and steer how the song is perceived. It is possible to take a somewhat sadder or dark chord progression and use the melody to change the mood to something more positive. Often this would require changing the key of the song, but that’s a perfectly acceptable way to write.