The string quartet as chamber music
There is a long history of studying the eighteenth-century string quartet from a structural or formal perspective. In general, musicologists have emphasized its evolution as a four-movement genre which employs a particular sequence of forms. Thus, the eighteenth-century string quartet is viewed as a metaphor for musical classicism, rather than as a form of chamber music. Chamber music of the mid-eighteenth century was known under a variety of names: divertimento, concerto, quartet, symphony, cassatio, nottumo, serenade, and partita. Idioms were undefined. A musical conversation is not just strict imitation as in a fugue or canon, but describes a condition where an idea, which turns and changes, can be passed from voice to voice. In a true musical conversation, each voice is differentiated by contrasting melodic shapes, phrase lengths, and rhythms. All of the types as well as the French quatuor concertant were written concurrently and throughout the second half of the eighteenth century.