Sonatina is a musical term that refers to a composition structure similar to that of a sonata, but with a shorter length and simpler form. There are a few synonyms that can be used to refer to a sonatina, including sonatine, petite sonata, and little sonata. Additionally, the term 'intermezzo' is also used to refer to a shorter musical composition that is often performed between larger works, which could also be used to describe a sonatina. Regardless of what terminology is used, the structure of sonatinas often features a fast opening movement, a lyrical slow movement, and a lively final movement.