At this period he had composed his first Mass in F, a work which, though crude and faulty, is remarkable as the effort of a self-taught genius. By this time, also, he had finished his first opera, "Der Neue Krumme Teufel," for which he was paid twenty-four ducats, but of which only the libretto is extant. It was produced at the Stadttheatre in 1752, and as it was also given in Prague, Berlin and other cities, it would appear that it was successful. Judging by those operas by Haydn that have come down to us, the disappearance of the score of his first work in that class is not to be greatly lamented. His muse was essentially undramatic, yet with that peculiar blindness to the true bent of his talents, a blindness far from uncommon among men of genius, he entertained a firm faith that it was his mission to write operas. Fortunately his opportunities to indulge his idiosyncrasy were not of a nature to enable him to turn from the path in which he was to win fame, although he composed in addition to the opera named, thirteen Italian and five Marionette operas, of which nothing has survived or has deserved to survive. Haydn was destined to revolutionize instrumental music; but the man who was to revolutionize the opera was yet to come and was to be called Mozart. Among Haydn's other compositions at this period were some clavier sonatas written by him for his pupils. They were the fruits of his study of the first six sonatas of C. Ph. Emanuel Bach, to which he devoted himself untiringly. Haydn said, "I played them constantly and did not rest until I had mastered them all, and those who know my music must also know that I owe very much to Emanuel Bach." In fact Haydn prided himself greatly because he had been once complimented by Bach for his knowledge of that composer's works. One of these sonatas by Haydn had attracted the attention of the Countess Thun, an enthusiastic amateur of music, who expressed a desire to see him. He called on her and surprised her by his youthful appearance and distressed her by the shabbiness of his attire. The evil fortune that always kept him in want during his early years was again accompanied by the good fortune that at every crucial stage of his youthful career brought him into contact with influential friends who assisted him. The Countess questioned him about himself. In response to her inquiries he gave her a straightforward account of his situation, on hearing which she presented him with twenty-five ducats and engaged him to give her lessons on the harpsichord and in singing. His prospects brightened, and as pupils began to increase in number he raised his charge for lessons from two to five florins ($2.50)--a month! An additional piece of good fortune came to him at this stage of his prosperity in the acquaintance of Baron Fürnberg, a rich nobleman and an ardent and talented amateur, to whose house Haydn was invited. Here private concerts were