The Morzin orchestra performed Haydn's first symphony, which he conducted from the harpsichord. .

             On November 26, 1760, he married Maria Anna Keller. Maria Anna, who was Joseph's elder by four years, was bad tempered, disliked music, and was unable to clean the house or bear children. She enjoyed making Joseph angry, and often used his compositions as tablemats. As a result, the couple fought often, and the marriage was a total disaster. He retreated into his music, while she found consolation by spending a great deal of time in church. .

             In 1761, Count Morzin was forced to disband his orchestra due to financial problems. It wasn't long, however, before Haydn was offered another job, this time in Eisenstadt, Austria, as assistant Kapellmeister for Prince Paul Anton Esterhazy, who was greatly impressed by the music that Haydn performed while he was with the Morzin orchestra. .

             Paul Anton died in 1762 and was succeeded by his brother Nicholas, who was also a music lover and played the baryton (a brass wind instrument). Thus, Haydn composed more than a hundred trios for baryton, viola, and bass during the next thirteen years. Haydn also composed several short operas and a full-length opera, named Acide.

             Upon the death of Gregor Werner in 1766, Joseph Haydn was promoted to Kapellmeister (musical director). Prior to his death, Werner earned slightly over half of the wage paid to his highly talented, younger assistant. The orchestra was expanded, and Haydn composed four to five symphonies a year. He also continued to compose operas. .

             In 1768, Haydn and the Esterhazy orchestra moved to Eszterhaza, a beautiful new palace built by Prince Nicholas. During this time, Haydn did not maintain his usual volume of symphony production, as he composed less than ten between 1766 and 1770. However, Haydn experienced a renewed interest in writing string quartets. He composed three groups of six quartets between 1771 and 1772, which he published with the opus Nos.