Before completing his thirteenth year, Ludwig obtained his first official appointment from the Elector; he became what is called cembalist in the orchestra, which meant that he had to play the piano in the orchestra, and conduct the band at rehearsals.    From Wordnik.com.  [The World's Great Men of Music Story-Lives of Master Musicians] Reference

Philip Emanuel, had entered the service of Frederick the Great, and was acting as cembalist in the royal orchestra.    From Wordnik.com.  [Story-Lives of Great Musicians] Reference

The duty of the cembalist is to preside at the piano.    From Wordnik.com.  [Beethoven A Character Study]

Carl Philip Emmanuel, his third son, was cembalist in the royal orchestra of Frederick the Great.    From Wordnik.com.  [The World's Great Men of Music Story-Lives of Master Musicians] Reference

Neefe was soon after promoted, the Elector giving him charge of the secular as well as the sacred music of the Court, upon which Beethoven received his first appointment, that of cembalist of the orchestra.    From Wordnik.com.  [Beethoven A Character Study]

(cembalist), having to prepare the operas, adapt them to the orchestra and the players of the theater, and sometimes to train the whole company for several months together, while Neefe, the director, was away.    From Wordnik.com.  [A Popular History of the Art of Music From the Earliest Times Until the Present] Reference