inspired efforts.

The fourth act opens in Masaniello's cottage. He deplores the coming
horrors of the day in a grand aria ("Dio! di me disponesti") which is
very dramatic in its quality. Fenella enters, and after describing the
tumult in the city sinks exhausted with fatigue. As she falls asleep
he sings a slumber song ("Scendi, o sonno dal ciel"), a most exquisite
melody, universally known as "L'Air du Sommeil." It is sung by the
best artists mezzo voce throughout, and when treated in this manner
never fails to impress the hearer with its tenderness and beauty. At
its close Pietro enters and once more rouses Masaniello to revenge by
informing him that Alphonso has escaped. After they leave the cottage,
the latter and Elvira enter and implore protection. Fenella is moved
to mercy, and a concerted number follows in which Masaniello promises
safety and is denounced by Pietro for his weakness. In the finale, the
magistrates and citizens enter, bearing the keys of the town and the
royal insignia, and declare Masaniello king in a chorus of a very
inspiriting and brilliant character.

The last act is very powerful, both dramatically and musically. It
opens in the grounds of the Viceroy's palace, and Vesuvius is seen in
the distance, its smoke portending an eruption. Pietro and companions
enter with wine-cups in their hands, as from a banquet, and the former
sings a barcarole ("Ve' come il vento irato"). At its close other
fishermen enter and excitedly announce that troops are moving against
the people, that Vesuvius is about to burst into flame, and that
Masaniello, their leader, has lost his reason. This is confirmed by
the appearance of the hero in disordered attire, singing music through
which are filtered fragments of the fishermen's songs as they rise in
his disturbed brain. This scene, the third in the act, is one not only