That grand work, the "Zauberflöte," had just been completed when a strange commission was given him. One day a tall, haggard-looking man, dressed in gray, with a very sombre expression of countenance, called upon Mozart, bringing with him an anonymous letter. This letter contained an inquiry as to the sum for which he would write a mass for the dead, and in how short a time this could be completed. Mozart consulted his wife, and the sum of fifty ducats was mentioned. The stranger departed, and soon returned with the money, promising Mozart a further sum on completion, and also mentioned that he might as well spare the trouble of finding out who had given this commission, for it would be entirely useless. We now know that the commission had really been given by Count Walsegg, a foolish nobleman, whose wife had died, and who wanted, by transcribing Mozart's score, to pass it off as his own composition--and this he actually did after the composer's death. Poor Mozart, in the weak state of health in which he now was, with nerves unstrung and over-excited brain, was strangely impressed by this visit, and soon the fancy took firm possession of him that the messenger had arrived with a mandate from the unseen world, and that the "Requiem" he was to write was for himself. Not the less did he ardently set to work on it. Hardly, however, was it commenced than he was compelled to write another opera, "La Clemenza di Tito," for which a commission had been given him by the Bohemian Estates, for production on the occasion of the Emperor Leopold's coronation in their capital. This was accomplished in the short space of eighteen days, and though it does not contain the best music, yet the overture and several of the numbers are full of a piquant beauty and liveliness well suiting the festival of a people's rejoicing. But a far greater work, the "Zauberflöte," was produced in Vienna shortly afterward. It did not take very well at first, but subsequent performances went better. [Illustration: Mozart Singing his Requiem.]