Is the concepts of departure and return very important in sonata-allegro form?

In sonata-allegro form, the concepts of departure and return are indeed highly significant. The departure refers to the moment in the exposition section where the music modulates to a new key, typically the dominant or relative major/minor key. This departure creates a sense of contrast and tension, as the music moves away from the home key. The return, on the other hand, signifies the moment in the recapitulation section where the music returns to the home key, bringing a sense of resolution and closure to the piece.

Understanding departure and return becomes crucial for analyzing and interpreting the structure and emotional impact of sonata-allegro form. The departure often creates a sense of anticipation and yearning for the eventual return to the home key. This journey away from and back to the home key forms the core of the sonata-allegro's dramatic narrative.

Through departure and return, composers can create moments of musical contrast, tension, and release. These concepts contribute to the dynamic and engaging nature of sonata-allegro form, making it a fundamental principle in Western classical music.