Let us think about what triads mean in music. By adding one more 3rd from an interval 3rd, the three pitches become a triad. It is a very basic form of chord, and the progression of chords creates harmony. Harmony functions as one of the fundamentals in most music styles, including pop, classical, folk, and jazz, by supporting melody, generating color, producing background, or being itself as a main character. Tons of music, especially songs, are made of two parts: melody and accompaniment. They are closely connected, but melody usually leads the song while accompaniment provides harmony.
The importance of harmony is tremendous. We often can imagine an accompanying harmony when singing a song or playing a melody. We instantly recognize harmony because it’s a process intertwining vertically and horizontally with other parts, especially melody.
The creative project in this chapter, therefore, is to compose a melody for a lullaby based on the given harmony. Making the accompaniment for the given melody will be introduced in the next chapter.