'Così fan tutte,' his next work, was produced at Vienna in January, 1790. It has never been so successful as its two predecessors, chiefly on account of its libretto, which, though a brisk little comedy of intrigue, is almost too slight to bear a musical setting. The plot turns upon a wager laid by two young officers with an old cynic of their acquaintance to prove the constancy of their respective sweethearts. After a touching leave-taking they return disguised as Albanians and proceed to make violent love each one to the other's fiancée. The ladies at first resist the ardent strangers, but end by giving way, and the last scene shows their repentance and humiliation when they discover that the too attractive foreigners are their own lovers after all. There is much delightful music in the work, and it is greatly to be regretted that it should have been so completely cast into the shade by 'Le Nozze di Figaro,'
Mozart's next opera, 'La Clemenza di Tito,' was hastily written, while he was suffering from the illness which in the end proved fatal. The libretto was an adaptation of an earlier work by Metastasio. Cold and formal, and almost totally devoid of dramatic interest, it naturally failed to inspire the composer. The form in which it was cast compelled him to return to the conventions of opera seria, from which he had long escaped, and altogether, as an able critic remarked at the time, the work might rather be taken for the first attempt of budding talent than for the product of a mature mind. The story deals with the plotting of Vitellia, the daughter of the deposed Vitellius, to overthrow the Emperor Titus. She persuades her lover Sextus to conspire against his friend, and he succeeds in setting the Capitol on fire. Titus, however, escapes by means of a disguise, and not only pardons all the conspirators, but rewards Vitellia with his hand. The opera was produced at Prague on the 6th of September, 1791, and the cold reception which it experienced did much to embitter the closing years of Mozart's life.
'Die Zauberflöte,' his last work, was written before 'La Clemenza di Tito,' though not actually produced until September 30, 1791. The libretto, which was the work of Emanuel Schikaneder, is surely the most extraordinary that ever mortal composer was called upon to set.
At the opening of the opera, the Prince Tamino rushes in, pursued by a monstrous serpent, and sinks exhausted on the steps of a temple, from which three ladies issue in the nick of time and despatch the serpent with their silver spears. They give Tamino a portrait of Pamina, the daughter of their mistress, the Queen of Night, which immediately inspires him with passionate devotion. He is informed that Pamina has been stolen by Sarastro, the high-priest of Isis, and imprisoned by him in his palace. He vows to rescue her, and for that purpose is presented by the ladies with a magic flute, which will keep him safe in every danger, while Papageno, a bird-catcher, who has been assigned to him as companion, receives a glockenspiel. Three genii are summoned to guide them, and the two champions thereupon proceed to Sarastro's palace. Tamino is refused admittance by the doorkeeper, but Papageno in some unexplained way contrives to get in, and persuades Pamina to escape with him. They fly, but are recaptured by Monostatos, a Moor, who has been appointed to keep watch over Pamina. Sarastro now appears, condemns Monostatos to the bastinado, and decrees that the two lovers shall undergo a period of probation in the sanctuary. In the second act the ordeal of silence is imposed upon Tamino. Pamina cannot understand his apparent coldness, and is inclined to listen to the counsels of her mother, who tries to induce her to murder Sarastro. The priest, however, convinces her of his beneficent intentions. The lovers go through the ordeals of fire and water successfully, and are happily married. The Queen of Night and her dark kingdom perish everlastingly, and the reign of peace and wisdom is universally established. The humours of Papageno in his search for a wife have nothing to do with the principal interest of the plot, but they serve as an acceptable contrast to the more serious scenes of the opera.
The libretto of the 'Die Zauberflöte' is usually spoken of as the climax of conceivable inanity, but the explanation of many of its absurdities seems to lie in the fact that it is an allegorical illustration of the struggles and final triumph of Freemasonry. Both Mozart and Schikaneder were Freemasons, and 'Die Zauberflöte' is in a sense a manifesto of their belief. Freemasonry in the opera is represented by the mysteries of Isis, over which the high-priest Sarastro presides. The Queen of Night is Maria Theresa, a sworn opponent of Freemasonry, who interdicted its practice throughout her dominions, and broke up the Lodges with armed force. Tamino may be intended for the Emperor Joseph II., who, though not a Freemason himself as his father was, openly protected the brotherhood; and we may look upon Pamina as the representative of the Austrian people. The name of Monostatos seems to be connected with monasticism, and may be intended to typify the clerical party, which, though outwardly on friendly terms with Freemasonry, seems in reality to have been bent upon its destruction. Papageno and his wife Papagena are excellent representatives of the light-hearted and pleasure-loving population of Vienna. It is difficult to make any explanation fit the story very perfectly, but the suggestion of Freemasonry is enough to acquit Mozart of having allied his music to mere balderdash; while, behind the Masonic business, the discerning hearer will have no difficulty in distinguishing the shadowy outlines of another and a far nobler allegory, the ascent of the human soul, purified by suffering and love, to the highest wisdom. It was this, no doubt, that compelled Goethe's often expressed admiration, and even tempted him to write a sequel to Schikaneder's libretto. 'Die Zauberflöte' is in form a Singsgiel—that is to say, the music is interspersed with spoken dialogue—but there the resemblance to Hiller's creations ceases. From the magnificent fugue in the overture to the majestic choral finale, the music is an astonishing combination of divinely beautiful melody with marvels of contrapuntal skill. Perhaps the most surprising part of 'Die Zauberflöte' is the extraordinary ease and certainty with which Mozart manipulates what is practically a new form of art. Nursed as he had been in the traditions of Italian opera, it would not have been strange if he had not been able to shake off the influences of his youth. Yet 'Die Zauberflöte' owes but little to any Italian predecessor. It is German to the core. We may be able to point to passages which are a development of something occurring in the composer's earlier works, such as 'Die Entführung,' but there is hardly anything in the score of 'Die Zauberflöte' which suggests an external influence. Its position in the world of music is ably summarised by Jahn: 'If in his Italian operas Mozart assimilated the traditions of a long period of development and in some sense put the finishing stroke to it, with "Die Zauberflöte" he treads on the threshold of the future, and unlocks for his country the sacred treasure of national art.'
Of Mozart's work as a whole, it is impossible to speak save in terms which seem exaggerated. His influence upon subsequent composers cannot be over-estimated. Without him, Rossini and modern Italian opera, Weber and modern German, Gounod and modern French, would have been impossible. It may be conceded that the form of his operas, with the alternation of airs, concerted pieces and recitativo secco, may conceivably strike the ears of the uneducated as old-fashioned, but the feelings of musicians may best be summed up in the word of Gounod: 'O Mozart, divin Mozart! Qu'il faut peu te comprendre pour ne pas t'adorer! Toi, la vérité constante! Toi, la beauté parfaite! Toi, le charme inépuisable! Toi, toujours profond et toujours limpide! Toi, l'humanité complète et la simplicité de l'enfant! Toi, qui as tout ressenti, et tout exprimé dans une langue musicale qu'on n'a jamais surpassée et qu'on ne surpassera jamais.'