The reader must bear in mind the important fact that instrumental music, pure and simple, was still young, and that composers were chiefly engaged in developing musical beauty. The technics of instrumental writing were not sufficiently advanced to admit of high emotional expression. The reader will remember that in the old schools of church counterpoint the technics of the art were developed by Okeghem, after which Josquin des Prés showed how to write beautifully, and the masters of the last period discovered how to make beauty go hand in hand with expression. So the early writers of the sonata were chiefly engaged in experimenting with the technics of their new form and the instruments for which they wrote, and this paved the way for Haydn and Mozart, when once the former had established the sonata form, to seek for pure beauty. This they found, and Mozart's works in particular abound with it. The time was now at hand when the sonata form was to be made the vehicle for the expression of the most profound human emotion. But before it could achieve that end, something had to be added to its technic and its organization. Part of this addition was made by Clementi. Muzio Clementi (1752-1832) was born before Beethoven and died after him. His works show that he at first influenced Beethoven but was afterward influenced by him. Clementi's masculine treatment of the piano, which we have already noticed, went far toward leading Beethoven away from the thin style of Haydn and Mozart. There are many passages in Clementi's early sonatas which are similar in construction to passages afterward written by Beethoven. Again, Clementi extended and elaborated the "working out" part, and sometimes introduced into the body of a movement phrases from its introduction. But the works of Beethoven speedily superseded those of Clementi, and it is to these we must now turn our attention. Fortunately they call for only brief discussion, for Beethoven's sonatas are more remarkable for their content than for their form.