What is the significance of diatonic scales in music theory and how do they contribute to the overall harmonic structure of a piece?

Diatonic scales are important in Music Theory because they provide the foundation for creating harmonies and melodies that sound pleasing to the ear. These scales consist of seven notes that follow a specific pattern of whole and half steps. By using diatonic scales, composers can establish a key center and create chord progressions that form the harmonic structure of a piece. This helps to give a sense of stability and coherence to the music, allowing listeners to follow and appreciate the overall musical journey.