Johann Michael Haydn (1732-1809), the younger brother of Joseph Haydn, was born in Rohrau, a village that at that time stood on the border with Hungary. Neither parent could read music; however, his father Mathias was an enthusiastic folk musician, who during the journeyman period of his career had taught himself to play the harp.
Michael went to Vienna at the age of eight, his early professional career path being paved by his older brother Joseph, whose skillful singing had landed him a position as a boy soprano in the St. Stephen's Cathedral, Vienna. By his 12th birthday he was earning extra money as a substitute organist at the cathedral and had, reportedly, performed preludes and fantasies of his own composition.
In 1760 Michael was appointed concertmaster at Großwardein (today Oradea) and in 1762 at Salzburg, where he remained for 44 years, during which he wrote over 360 compositions.
Michael Haydn was acquainted with Leopold and Wolfgang Amadeus Mozart, who held his work in high esteem. Also Joseph Haydn regarded his brother's music highly, to the point of feeling Michael's religious works were superior to his own.
In 1802 Michael Haydn was "offered lucrative and honourable positions" by "the Grand Duke of Tuscany", but in the end chose to stay in Salzburg.