The symphony in the early stages of the classical period, which began with Emmanuel Bach, followed pretty closely the lines of the piano sonata in form. E. Bach was at work writing symphonies when Haydn was a little boy. It must be confessed, however, that his symphonies are less distinct in form than his piano sonatas. It is because of the decided clearness of the orchestral works of Haydn that he is celebrated as the father of the symphony. He established the sonata form and it is not at all surprising that he applied it successfully to his orchestral compositions. Haydn wrote (or is said to have written) one hundred and eighteen symphonies, beginning in 1759 and continuing to his later years. His earliest works are so irregular and uncertain that they do not throw much light on anything except his instrumentation. His position as conductor of Prince Esterhazy's orchestra gave him abundant opportunity to experiment with instrumental forms and effects, and his symphonies written during his long service in the Esterhazy household show steady advance in style. The Esterhazy orchestra contained in 1766, six violins and violas, one 'cello, one double bass, one flute, two oboes, two bassoons, and four horns. It was afterward enlarged to twenty-two, including trumpets and kettle-drums. In 1776, after Haydn had learned from Mozart how to use clarinets, two of these instruments were added, making twenty-four in all. It was a pretty small orchestra according to our present ideas, but it sufficed for the establishment of the symphony.