Cassation is a minormusical genre related to the serenade and divertimento. In the mid-to-late 18th century, cassations commonly comprised loosely assembled sets of short movements intended for outdoor performance by orchestral or chamber ensembles. The genre was popular in southern German-speaking lands. Other synonymous titles used by German-speaking composers and cataloguers included Cassatio, Cassatione and Kassation. An equivalent Italian term was Cassazione. The genre is occasionally alluded to in the titles of some twentieth-century compositions.
Eighteenth-century genre
Works titled cassation were especially common in southern Germany, Austria and Bohemia in the mid-to-later part of the eighteenth century. Some early works by Joseph Haydn and Wolfgang Amadeus Mozart bear the title cassation; other composers of the classical and pre-classical era who produced cassations include Franz Joseph Aumann, Carl Ditters von Dittersdorf, Michael Haydn, Leopold Hofmann, Antonio Rosetti, Joseph Schmitt, Johannes Sperger and Johann Baptist Wanhal. Leopold Mozart's Toy symphony was a reduction of his earlier Cassation in G. The Italianized term, cassazione, appears to have been used by Antonio Salieri. It is hard to discern any substantive formal characteristic that could distinguish cassations from other serenade-like genres, such as the divertimento, notturno, or Finalmusik. It seems likely that the term cassation was used to refer to the intended social function of the music as outdoor entertainment rather than any particular structural features. Breitkopf's thematic catalogues of the time tended to apply titles such as "cassation" and "divertimento" rather interchangeably, as did the composers themselves. This terminological overlap makes it difficult to distinguish formal characteristics of the cassation as a musical genre. Both Wolfgang Amadeus Mozart and Michael Haydn seem to have used the term only to refer to orchestral pieces, whereas Joseph Haydn called his op. 1 and op. 2 string quartets "cassations". Instrumental and orchestral cassations seem to be stylistically linked to the divertimento and serenade, respectively. By the end of the eighteenth century, the term had fallen out of fashion.
The etymology of the musical term is uncertain. Mozart’s cassations K. 63 and K. 99 open with marches, and the term has been speculatively linked to the Italian wordcassa, meaning "drum". Hermann Abert was among those who thought that the term derives from the Italian cassare, meaning "to dismiss", implying a musical farewell, or Abschiedsmusik. The French word casser was also invoked, based on the notion that the movements could be freely broken up into any order. A more likely derivation, reflecting the outdoor character of the genre, involves a transformation of the Austrian dialectal word gassatim: specifically, gassatim gehen was an expression commonly used by local eighteenth-century musicians to refer to street performance.
