A violin sonata is a type of musical piece. It's usually written for a violin and piano, but sometimes there is only a violin. A violin sonata is made up of several different sections, like a story with different chapters. Each chapter tells a different part of the story. During a violin sonata, the violin and the piano will often alternate between playing the melody, which is the main tune, and the accompaniment, which helps to make the piece sound full and beautiful.