information:classification, structural:scholar_edition, stylistic:tone, quality:correction
Collapse of the aristocratic system

Throughout the 18th century, the composer was normally an employee of an aristocrat, and the chamber music he or she composed was for the pleasure of aristocratic players and listeners. Haydn, for example, was an employee of Nikolaus I, Prince Esterházy, a music lover and amateur baryton player, for whom Haydn wrote many of his string trios. Mozart wrote three string quartets for the King of Prussia, Frederick William II, a cellist. Many of Beethoven's quartets were first performed with patron Count Andrey Razumovsky on second violin. Boccherini composed for the king of Spain.

With the decline of the aristocracy and the rise of new social orders throughout Europe, composers increasingly had to make money by selling their compositions and performing concerts. They often gave subscription concerts, which involved renting a hall and collecting the receipts from the performance. Increasingly, they wrote chamber music not only for rich patrons, but for professional musicians playing for a paying audience.