According to Albert Christoph Dies, an early biographer of Joseph Haydn, Johann followed his older brothers in serving as a choirboy in St. Stephen's Cathedral in Vienna.
[3] In 1765, after his stepmother had remarried, Johann left home and joined his brother Joseph, who by this time was employed in Eisenstadt as Kapellmeister to the Esterházy family.
Johann worked without pay, supported by his brother, for six years, after which he drew a small salary, which Joseph supplemented.
[5] Perhaps as a result, his services to the Esterházy family were limited to church music; he was not recruited to perform in any of the many operas directed by Joseph starting in the 1770s.
Johann briefly lost his job in 1775 when some "minor infraction" (Robbins Landon) brought upon him the wrath of Prince Nikolaus's estates director, the short-tempered Peter Ludwig von Rahier.