Act II. News of the success of the Egyptian expedition against the Ethiopians has reached Amneris, whose slaves attire her for the scene of Radames's triumph. The slaves sing of Egypt's victory and of love, the princess of her longing, and Moorish slaves dance before her to dispel her melancholy. Aïda comes, weighed down by grief. Amneris lavishes words of sympathy upon her, and succeeds in making her betray her love for Radames by saying that he had been killed in battle. Then she confesses the falsehood and proclaims her own passion and purpose to crush her rival, who shall appear at the triumph of Radames as her slave. Aïda's pride rebels for the moment, and she almost betrays her own exalted station as the daughter of a king. As a slave she accompanies the princess to the entrance gate of Thebes, where the King, the priests, and a vast concourse of people are to welcome Radames and witness his triumphal entry. Radames, with his troops and a horde of Ethiopian prisoners, comes into the city in a gorgeous pageant. The procession is headed by two groups of trumpeters, who play a march melody, the stirring effect of which is greatly enhanced by the characteristic tone quality of the long, straight instruments which they use:-- [Musical excerpt] A word about these trumpets. In shape, they recall antique instruments, and the brilliancy of their tone is due partly to the calibre of their straight tubes and partly to the fact that nearly all the tones used are open--that is, natural harmonics of the fundamental tones of the tubes. There is an anachronism in the circumstance that they are provided with valves (which were not invented until some thousands of years after the period of the drama), but only one of the valves is used. The first trumpets are in the key of A-flat and the second B-natural, a peculiarly stirring effect being produced by the sudden shifting of the key of the march when the second group of trumpeters enters on the scene. The King greets Radames with an embrace, bids him receive the wreath of victory from the hands of his daughter and ask whatever boon he will as a reward for his services. He asks, first, that the prisoners be brought before the King. Among them Aïda recognizes her father, who is disguised as an officer of the Ethiopian army. The two are in each other's arms in a moment, but only long enough for Amonasro to caution his daughter not to betray him. He bravely confesses that he had fought for king and country, and pleads for clemency for the prisoners. They join in the petition, as does Aïda, and though the priests warn and protest, Radames asks the boon of their lives and freedom, and the King grants it. Also, without the asking, he bestows the hand of his daughter upon the victorious general, who receives the undesired honor with consternation.