During 1830s the popularity of piano music increased drastically. This was because the Industrial Revolution allowed piano manufacturers to developed methods for building many more pianos at lower costs. Pianos were no longer so expensive that ownership was reserved exclusively for the wealthy. Middle class could also own them and make music at home greatly expanding the musical audience. The sonata was still used at court and to a lesser extent in the church. These locations are mainly due to the Baroque era, however, during the Classical period the sonata took on distinctly different functions. The sonata was a,"diversion of the amateur or dilettante, a launching vehicle for the professional composer and performer, a training resource for the student; an occasional item in private and public concerts; and a conventional music accessory in the church"(Newman 486). The sonata was basically used during small social gatherings, or as musical training. Another, and likely most important function of the sonata was as way for composers to become known. "Every musician who aspired to join the company of composers working for the public generally began his career with keyboard compositions, namely with solo sonatas"(Newman 487). .

             The first composers to significantly development the sonata during the Classical era were Haydn and Mozart. Little is known about Haydn's piano sonatas, even though his piano sonatas and string quartets stand apart from most of his other compositions. Haydn's initial works for the keyboard are reminiscent of the sonata and intended as an instructional aid (Larson 336). Following these, he composed fourteen sonatas. It is unknown who the sonatas were written for. They are difficult pieces to play and display few baroque concerto characteristics. However, they do exhibit "Haydn's originality and independence of fashion" (Larson 336). .

             Mozart was one of the sonata's first great composers, creating short keyboard compositions while still a young child.