What is the significance of the term "aba form" in music composition and how is it commonly used in creating musical structures?

The term "aba form" in music composition refers to a structure where a piece of music has three main sections: A, B, and A. The first section (A) presents a theme or melody, the second section (B) contrasts with a different theme, and the final section (A) repeats the original theme. This form is commonly used in creating musical structures because it provides a clear and balanced organization to the music, allowing for variation and development of themes while maintaining a sense of unity and coherence.