"Zoltán Kodály, a Hungarian composer and ethnomusicologist, lived from 1882-1967. In addition to composing countless beautiful pieces of music, he made it his mission to improve the state of music education in Hungary. He believed strongly that musical concepts could be taught through the music of the native people: in other words, the key to musical literacy was folk songs. Only the "best" music would do. Kodály was convinced that the "best music" is 1) the folk songs of the people, and 2) art songs composed by the "masters". Therefore, in 1905, he began traversing the Hungarian countryside and villages recording the folk music of the people with a phonograph. Aided by his friend and fellow composer Béla Bartók, he compiled and notated a huge collection of folk music with which to teach musical concepts to children. The human voice is the essence of his methodology, and is the means by which children learn music. Zoltán Kodály believed all children could sing, and that tone deafness was a myth (barring a physical disability). He insisted, "If we ourselves sing often, this provides a deep experience of happiness in music. Through our own musical activities, we learn to know the pulsation, rhythm, and shape of melody. The enjoyment given encourages the study of instruments and the listening to other pieces of music as well."
Kodály's approach is a "mother tongue" approach. Linguistically, we immerse our children in our native tongue from the time they are in utero. Once someone is literate, they can "hear" the words of a book as they are reading silently. Musical literacy produces the same effect. A child who is musically literate can see the musical symbols on a page and hear those symbols in their head. Children brought up learning in the Kodály methodology will learn music concepts through nursery rhymes and folk songs, and will later transfer that knowledge to art songs and classical music. This is like a child who learns to read simple phonetic readers, and is later able to devour the Great Books independently. The final outcome of the Kodály method is the development of the independent musician.
The curricula based on this methodology consists of a carefully ordered sequence of musical concepts, which follows logically with the natural development of the child. These concepts are isolated and extracted from the "music of the people" or familiar folk songs. A child's first pitches and rhythms are those found in games and nursery rhymes (think of "nanny-nanny boo-boo"). A child's life is paced more like an 8th note, so shorter durations like "ti-ti" (two eighth notes) are taught early on. Most modern music pedagogy would start with the whole note. The Kodály method also uses a very limited pitch set at first: the pentatonic scale. These are the pitches children naturally sing in tune, along with the descending 3rd or "so-mi" (think of "rain, rain, go away..."). By contrast, other modern methodology starts with "do-re-mi" and the diatonic scale (all 7 tones). In the Kodály method, there is a very structured way of teaching the concepts through three distinct stages: preparation, presentation, and practice. These stages are referred to as "The 3 P's". All learning modalities (kinesthetic, aural, and visual) are addressed throughout these three stages and the concepts are continually reinforced with games and practice techniques. The children are learning though play and are led to "discover" the concepts, which have already been internalized through games. The folk song is the medium through which they learn and achieve the goal of music literacy, and functions like the Great Books in the classical tradition. Music teachers receive intensive specialized training to master this methodology so they can better educate their students. At New Saint Andrews College in Moscow, Idaho, for instance, music teachers in classical settings receive training at their annual Chenaniah Summer Institute. The Kodály method has become the standard for classical music educators around the country.
You might be asking how this fits in with the Trivium, which is the Classical model of educating. More importantly, how does this methodology align with Classical CHRISTIAN education? In a classical education a child goes through the three stages of grammar, logic, and rhetoric. I liken these to the stages of knowledge, understanding, and wisdom, as outlined in Proverbs 24: 3, 4. Just as the Trivium follows the natural development of a human, the Kodály method follows the natural development of the child. God created us in His image, and He gifted us with the ability to sing and be musical. Not only is singing a gift from God, it's a Christian and human responsibility. There are countless imperatives in the Bible commanding us to sing. One example is Psalm 96:1: "O sing unto the Lord a new song: sing unto the Lord, all the earth." Notice it reads, "ALL the earth." We need to make singing and musical ability accessible to ALL. That is what the goal of the Kodály method is. God gave everyone a voice. It is something we can all use to praise Him and to proclaim His glory. And by following Kodaly's philosophy that "only the best will do" for a child, we are training our children to both discern and love what is good, true, and beautiful. We are equipping our children with the musical tools they need to worship, so they can make God known through the beauty of music. As a result, the truth of God can be effectively emanated.