What is the significance of diatonic in music theory and how does it influence the composition and structure of musical pieces?

In Music Theory, diatonic refers to a system of organizing musical notes within a key. It is significant because it provides a framework for creating harmonious and coherent melodies and chords. Diatonic scales and chords are the foundation of most Western music, influencing the composition and structure of musical pieces by establishing a sense of tonal center and guiding the progression of harmonies.