Although Haydn was not a virtuoso on every instrument, he had a profound understanding of their effect and potential. He was modest when speaking to Georg Griesinger, emphasizing that even if he didn't possess the mastery of Mozart or Beethoven, he still played organ concerts at events in the hospital or for Count Harrach. In his role as Vice-Kapellmeister to the Esterházy family, he not only performed on the violin and piano but also committed many of his musical ideas to paper at the piano. When composing, Haydn particularly favored the clavichord, along with the harpsichord and fortepiano.
Haydn's artistic development is less clearly discernible in his more than 60 sonatas than in his symphonies or quartets; nevertheless, they reflect the progressive evolution of the classical sonata form. Inspired by the Empfindsamkeit (sensibility) of Emanuel Bach, these works display a wide range of influences and styles: while early pieces were often intended for young female students, later collections exhibit a more folk-oriented character. Haydn's music evolved through his encounter with new instruments and the influence of important contemporaries.
His compositions for keyboard instruments demonstrate a great stylistic diversity and technical mastery. From elegant turns of phrase to sophisticated harmonic structures, the range is vast; Haydn's sonatas offer a unique perspective on the development of the classical keyboard repertoire. His output spans from early harpsichord pieces to demanding works for the fortepiano and is always characterized by inventiveness and charm.
The maturity of Haydn's music is revealed in his sonatas, from his early to his late works. Collaborations with various publishers and dedications to prominent figures point to different creative phases. From the influence of Emanuel Bach to the innovative London Sonatas, Haydn's artistic development is clearly evident. From humble beginnings he developed into one of the most important instrumental composers in Europe and left behind an extraordinary musical legacy.