Serenade; Divertimento; Cassation; Notturno

 

Serenade

As a form, the Serenade is characterized by a mixture of elements taken from the suite, particularly marches and minuets, and from the sonata.  The style likewise is about midway between that of the suite and the symphony.  Serenades usually are written for a small ensemble consisting of a limited number of strings and a few wind instruments, as would be suitable for an open-air performance.  The most famous examples are Mozart's "Haffner" Serenade (K. 250) and "Eine kleine Nactmusik" (K. 525).
 

Divertimento

A term frequently used in the 18th century, especially in Austria, for an instrumental composition written primarily for entertainment and hence in a rather light vein.  The title Divertimento was given to an enormous variety of types.  Usually, however, such compositions were written for small ensembles (strings, winds, or mixed groups; three to eight or more players) and consisted of a number (three to ten) of relatively short movements, some of which are modeled after the sonata while others are dances (especially minuets), marches, or variations.  In one of his autograph catalogs Haydn used the title Divertimento for 162 compositions, among them his Baryton trios.  More than 50 of them are divertimenti as defined here.  Mozart wrote 37 compositions called Divertimento.
 

Cassation

An instrumental form of the 18th century, designed for outdoor performance, that includes elements of the symphony as well as the suite;  hence, practically identical with the divertimento and serenade.
 

Notturno

An 18th-century name for compositions similar to the serenade, designed to be played as an evening entertainment.