It is not easy to make a list of the organ concertos by Joseph Haydn. First of all there are some doubts about the author. Once ten concertos were attributed to Haydn, but now there are some serious doubt as to four of them are Haydn's at all. Secondly  there is the choice of the solo instrument. In the second half of the 18th century the German word ‘Klavier’ could mean at least four instruments: pianoforte, harpsichord, organ en clavichord. The last one is the first to drop out, for instance because of the very soft sound, which makes the clavichord not appropriate as solo instrument in a concerto. The pianoforte is an instrument that gets a more prominent role in Haydn's later works and is not yet in the picture of his position as 'Kapelmeister' at the court of Esterhazy.

There are some indications that suggest that also Haydn himself had the organ or harpsichord in mind for instance for the Concerto in C Hob.XVIII, because he has written that down in the so-called ‘Entwurf-Katalog’ which he made of his own works.

In these early concerto's it is not about 'showing off' ones solistic qualities, but more about the creative mixture and combining of solo and tutti, and the finding of new colours and of course Haydn's always sparkling theme's.