1) The act of annulling 2) Western classical music style 
[music] Cassation is a minor musical 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 us...
annulment; overthrow of legal decision
• (n.) The act of annulling.
in music, 18th-century genre for orchestra or small ensemble that was written in several short movements. It was akin to the 18th-century serenade ... [1 related articles]
Cas·sa'tion noun [ French cassation . See Cass .] The act of annulling. « A general cassation of their constitutions. Motley. » Court of cassation ,