String quartet movements with a large-scale structure similar to that of a symphony: Substantial modifications to the typical structure were already achieved in Beethoven's later quartets, and despite some notable examples to the contrary, composers writing in the twentieth century increasingly abandoned this structure. Many other chamber groups can be seen as modifications of the string quartet: Further expansions have also been produced such as the String octet by Mendelssohn. Notably, Schoenberg included a soprano in the last two movements of his second string quartet, composed in 1908. This instrumentation of adding a voice is succeeded by Hindemith , Finzi, Respighi, Ginastera,
String quartet is often in Rondo form or Sonata rondo form, in the tonic key. Some quartets play together for many years in ensembles which may be named after the first violinist (e.g. the Takács Quartet), a composer (e.g. the Borodin Quartet) or a location (e.g. the Budapest Quartet). Well-known string quartets can be found in the list of string quartet ensembles. The early history of the string quartet is in many ways the history of Haydn's journey with the genre. Not that he composed the first quartet of all: before Haydn alighted on the genre there had been several spasmodic examples