Judging from his own words, the simplicity of the action did not deter the composer from employing extensively all aids to his art. In order to do full justice to his music we must remember his great successor who, much more richly endowed and filled with a spirit of a new time, far surpassed him as a musician—Mozart, who in this case could confirm the old saying: "Let well enough alone." Still more, if we look backward and contrast the greatest representative of the older Italian opera, Handel, with Gluck, we are astonished at the progress made by opera-music through the former. The old-fashioned ornate music of Handel has disappeared; true expression has gained the supremacy, although it never reigns at the expense of the melody which is almost inexhaustible and in its grace betrays in every measure the country whence it came. The celebrated aria "Che farò senza Euridice" is an example of Gluck's power to harmonize the greatest nobility of sentiment with the insinuating charm of melody. A sharp characterization corresponding to modern emotion is of course excluded here, and one of Gluck's French critics is not incorrect in his assertion that one can sing to the aforesaid air "J'ai trouvé mon Euridice" as well as "J'ai perdu mon Euridice." (I have found my Euridice as well as I have lost my Euridice.)
In the part of Euridice and in the duet of husband and wife, Gluck's power of musical delineation is even greater, but most impressive are the choruses in which the influence of the Handel oratorios is unmistakable. The chorus of the furies forbidding Orpheus the entrance to Hades is one of the most affecting, most impressive in the entire province of dramatic music, and serves to heighten the restful effect of the graceful ballet of a chorus of blessed spirits led by a flute solo, which immediately follows. Here the effect produced by the orchestra must not be overlooked, neither the modest means of this orchestra, which in the "Dance of the Furies" consists merely of a string quartette, two horns, oboe and flageolet.
As regards the music, the "Alceste" is more admirable than the "Orpheus," in that the uniformity of the libretto has put the skill of the composer to the more severe test. Even J. J. Rousseau averred that he knew of no opera in which the expression of the passions was more uniform than in "Alceste "; that all revolved about the two conditions of the soul, love and fear, and to describe these two sensations over and over again without monotony, required the composer's utmost skill. Rousseau makes also the just criticism that in the last act, where a climax is most needed to hold the listeners to the end, the interest flags. In point of fact the action of the "Alceste" is more feeble than that of "Orpheus." In agreement with Gluck, Calzabigi has preserved in his poetry the entire strength and simplicity of his prototype, the "Alceste" of Euripides; even the element of the unexpected which appears in "Orpheus" is not here employed. Admetus, King of Thessaly, is dangerously ill; his death is hourly expected. Apollo, who once, when driven from Olympus, found favor with the King, wishes to express his gratitude and causes his oracle to proclaim that if another person will voluntarily die for him, Admetus shall live. While the people, horrified, take flight, Alceste declares herself ready to sacrifice her life for her beloved husband. She dies, but Apollo (not Hercules, as in Euripides) appears at the same instant, rescues her from death and restores her to her family and people.
In his "Alceste" Gluck has exercised all his talent as composer in order to give the most intense musical expression to the evangel of devoted, self-sacrificing love. Naturally, it is to the noble, touching figure of the queen, wife and mother that he devotes the greatest love and care. Courageously she faces death with the words of the famous aria, "Ombre, larve, compagne di morte"; and the tenderest mother speaks in her when in parting from her children she makes her last petition: "Venite sovente alia mia tomba ornatela di fiori."
Further, the choruses in "Alceste" are overpowering in effect, which fact indicates a step in advance of "Orpheus" in so far that here the orchestra conduces infinitely more to the portrayal of the situation. Even in the first mentioned arias of "Alceste" the instruments, especially the trumpets, are employed in the most telling manner. Still more stirring is the orchestral action following the decree of the oracle, in the chorus "Fuggiamo!" Scarcely have the words of the gods died away when the basses are heard, in dull, sustained tones, descriptive of the murmur of the multitude. The murmuring grows louder and individual cries are heard until finally the entire mass of orchestra and chorus unites in the cry: "Let us away!" The full power of the Gluck orchestra, however, is revealed in the chorus of the gods of death which is sung upon one key by the basses, while the melody is sustained by the instruments. As an orchestral piece of the highest, most imperishable worth the sacrificial march in the first act deserves special mention. In this the melody, sustained simply by stringed instruments and low flutes, is quite different in character from ordinary marches and cannot fail to produce upon the mind of the hearers the mood corresponding to the high religious action.
Of "Paris and Helen" the reader knows already that, in spite of the sanguine hopes of the composer, the work was decidedly rejected by the public. He will remember also that Gluck, in this case, was not disposed to recognize the "vox populi" as the "vox dei," as he gave vent to indignation at his failure in the dedication of the work to the Duke of Braganza. Later, however, he must have acknowledged the justice of the judgment pronounced by the Viennese public, proved, if in no other way, by the fact that he did not consider "Paris" suitable to appear at the Paris Opera with "Orpheus" and "Alceste." Still, this almost unknown opera has its significance in the resumé of the master's development. In his endeavor to draw a sharp contrast between the principal figures—the effeminate Phrygian and the pure, true Spartan maid—Gluck has gained perceptibly in this direction of his art, and in the vocal as well as in the orchestral parts the peculiarity of each distinct nation is expressed. This is apparent even in the overture, which is more nearly related to the drama than in the case of Gluck's former operas, in that certain of its motives are repeated in the course of the action.
The overture to "Paris and Helen" may serve as a bridge from those works to which Gluck had given his whole creative strength and in which he had, so to speak, surpassed himself, to the works of the Parisian period, which is commonly regarded as the master's third period, though incorrectly, for in point of fact, Gluck's activity is divided into but two sections: the time before and the time after his acquaintance with Calzabigi. This is not saying that Gluck, in the presence of a drama as important as "Iphigénie in Aulis," the first real drama which he undertook to set to music, took, as it were, new impetus in order to outdo himself if possible for the sake of the Paris public whose judgment he so thoroughly respected. This is demonstrated in the overture to the aforesaid opera which, corresponding to this sort of ideal prologue, transports us to a higher sphere, in which we are prepared for the drama. "Here, as in the overture to 'Don Juan,'" says Richard Wagner, "it is the struggle or at least the juxtaposition of two adverse elements which determines the movement of the piece. Even in the action of 'Iphigénie' these two elements appear. The army of Greek heroes is assembled for the purpose of a great mutual undertaking; inspired by the thought of this alone, all other human interest disappears before that of the masses. Opposed to this is the interest attaching to the preservation of a human life, the rescue of a tender maiden. With what characteristic perspicuity and truth has Gluck almost personified these contrasts! In what lofty proportion has he measured them and made such contrast that by this juxtaposition alone is the opposition, and in consequence the movement given! By the ponderousness of the principal motive advancing solemnly, the mass of the people united in one interest is recognized, while immediately in the succeeding theme the interest in the suffering, frail creature fills us with compassion. The repetition of this single contrast throughout the composition gives us the great idea of the Greek tragedy, filling us alternately with fear and pity. Thus we attain to the lofty, excited state which prepares us for a drama the highest meaning of which it reveals to us at the outset and so leads us to understand, according to this meaning, the action which immediately follows."
In his treatment of the subject-matter of "Iphigénie in Aulis," Gluck's co-worker, du Rollet, has closely followed Racine's tragedy of the same name, even as the latter followed the drama of Euripides. The army of the Greeks has embarked for Troy in order to avenge the insult to their country by the capture of Helen. In the harbor of Aulis the warriors are detained by a tedious calm because their leader, Agamemnon, has killed a stag sacred to Diana and called down upon himself the vengeance of the goddess. Kalchas, the high priest, inquires of the oracle what may be done to propitiate Diana and receives the terrifying answer that naught but a human sacrifice, even the daughter of the king, Iphigenia, can in any wise appease her wrath. At these words, paternal affection, pride, love of country and military glory wage a fearful battle in the heart of the king, who becomes still more desperate when his wife, Clytemnestra, appears at the camp with her daughter who is to be forthwith united in marriage to the hero Achilles. The murmurs of the warriors clamoring for the sacrifice and the repeated warning of Kalchas reveal the frightful truth to the unsuspecting one; but Iphigenia declares herself ready to obey the gods. She kneels at the altar and is about to receive her death-blow, when Achilles with his Thessalonian warriors hastens, by force of arms, to save his bride from sacrificial death. Kalchas, however, steps between the combatants and tells them that their zeal has already appeased the anger of the goddess; the altar is destroyed by lightning, a favorable wind arises and amidst gay dancing and songs of great rejoicing the reunion of the lovers is celebrated.