Franz Joseph Haydn (1732-1809) was an Austrian composer of the Classical period. He spent much of his career as a court musician for the wealthy Esterházy family and, during that time, was the most celebrated composer in Europe.
He was a friend and mentor of Mozart, a tutor of Beethoven, and the elder brother of composer, Michael Haydn.
A lot of uncertainty surrounds the keyboard concertos of Haydn, especially as for what instrument each of the concertos was originally intended. At the very least "klavier" could mean harpsichord, organ or piano. Musicologists seem to agree that Concerto No.10 in C is probably intended for the organ. If nothing else, the organ is wholly suited to this concerto.