Johann Sebastian Demar was born on 29 June 1763 in Gauaschach, Bavaria. He came from a family of musicians: his father was a music teacher, and his brother Joseph was a violinist in the court orchestra of the Grand Duke of Würzburg.
Demar studied with Franz Xaver Richter in Strasbourg and then became organist and music teacher in Wissembourg (Lower Alsace). He later travelled to Vienna and became a pupil of Haydn. In 1788 he went to Paris and in 1789 settled in Orléans as a music teacher. In 1806 he founded the Société des Concerts par Abonnement there, which he directed himself and which played an important role in the cultural life of the city. For a number of years Demar directed the musical training of the Garde Nationale d'Orléans. In 1815 he became organist at Saint-Paterne in Orléans, where he died on 25 July 1832.
The concerto dates from around 1790. It is in D major, with the solo horn changing to F in the middle movement. This key is frequently found in Baroque and pre-classical music (Joseph and Michael Haydn, Graun, Röllig), but rarely in the Classical period and the Romantic era that followed. In its layout the work can be assigned to the "cor mixte" register promoted by the horn player Frédéric Duvernoy. Whether it was composed for Duvernoy can only be surmised.
Since it contains no exposed high notes, this concerto can also be recommended to horn students. Technical agility is nevertheless required.