Musical compositions are works of art created by composers for the purpose of expressing their ideas and emotions through music. Etudes, sonatas, pieces, songs, opuses, serenades, rondos, suites, scherzi, and cantatas are all examples of musical compositions. Etudes are short pieces of music that focus on a particular technique or skill, while sonatas are longer works that usually have multiple movements. Pieces are shorter works that are often used as accompaniment to other works. Songs are vocal works with lyrics, while opuses are larger works that are often composed of several movements. Serenades are light, romantic works, while rondos are pieces with a recurring theme. Suites are collections of pieces that are usually related in some way, while scherzi are humorous works. Cantatas are large works that are usually composed of several movements and feature soloists and a chorus.