Understanding harmony requires a basic familiarity with the elements of music theory. Although this may sound difficult, the building blocks of harmony are actually quite simple. Once kids are able to understand simple numerical relationships they should be able to grasp how the basic elements of harmony work. The only requirement is that they each be able to count to eight. Children can have fun learning about harmony if you make it into a game. Use a live performance in the classroom to illustrate the theory.
Present the C major scale in terms of numbers. Harmony is created by playing more than one note at a time and these notes can be understood by their relationship to the root note. C is the root note in the key of C major. This is the best place to begin, because there are no sharps and flats. Make a handout for each child with the notes of the C major scale: C-D-E-F-G-A-B-C. Leave a blank space under each note for the kids to fill in the numbers 1-2-3-4-5-6-7-8.
Explain harmony in terms of chords. Chords are the easiest way to understand the idea of harmony. All songs have a specific key center and the key determines the harmonic possibilities. All the individual notes of the scale can be harmonized and built into chords. Introduce chord harmony by focusing on major chords. Explain to the kids that a major chord is constructed from the root, the third and the fifth note of the major scale. Explain that there are three major chords for every key and that the major chords are the I, IV and V chords, which are built on the root, the fourth and fifth notes of the scale. This allows them to see that a C major chord is constructed by adding C, E and G together and that the major chords for the key of C are C, F and G.
Explain how the rules for harmony are the same for every key. Give the kids a handout with a G major scale: G-A-B-C-D-E-F#-G. Ask them to number the notes, like they did for the C major scale, 1-2-3-4-5-6-7-8. Then ask them to construct a G major chord with the root, the third and the fifth. Next have them figure out what the I, IV and V chords are. They will see that a G major chord is constructed by adding G, B and D and that the major chords in G major are G, C and D. Emphasize that the rules for G major and C major are exactly the same. This should help students see harmony as a mathematical process.
Arrange a live musical performance for the class. Invite a guitar player or pianist to come and perform. Let her know that your are teaching the kids the fundamentals of music theory and harmony. A live performance can illustrate and provide concrete examples of the theory. Ask her to play a simple melody, such as "Twinkle, Twinkle, Little Star," using only single notes. Next, accompany the melody with the appropriate chords. Ask the kids to identify the I, IV and V chords by listening. Have the performer illustrate the same song in several different keys. This helps the kids to understand that even though the key is different, the harmonic relationship sounds the same.