At the church of the Mendicanti in Venice, Consuelo is the most gifted of all the pupils of the famous teacher, Porpora. Consuelo is a poor orphan child, and Porpora makes her his goddaughter. Before the death of her mother, Consuelo promises that she will one day become betrothed to Anzoleto, another poor musician of Venice.

Through the efforts of Anzoleto, Consuelo is engaged as the prima donna at the theater of Count Zustiniani, replacing Corilla, who also was Porpora’s student. Consuelo is a great success, but Anzoleto, who was also engaged in the theater at the insistence of Consuelo, is not much of a musician and is not well received. Anzoleto, afraid that he will be discharged, pretends to be in love with Corilla, thinking that he will be safe if both singers are in love with him. Porpora never liked Anzoleto, and at last he contrives to have Consuelo visit Corilla’s home. When they find Anzoleto there, Consuelo is so hurt that she leaves Venice at once, vowing that she will never set foot on the stage again and renouncing the false Anzoleto forever.

From Venice, Consuelo goes to Bohemia, where she is engaged by Count Rudolstadt as a companion for his niece, Amelia. This young noblewoman is betrothed to young Count Albert Rudolstadt, but she fears him because he seems to be insane. Albert often has visions in which he sees scenes of the past and often imagines himself to be the reincarnated body of some person long dead. When Albert first hears Consuelo sing, he calls her by her name, even though she took another name to hide her unhappy life in Venice. Albert tells Consuelo and the whole family that she is his salvation—that she was sent to remove the curse from him. Consuelo is bewildered.

Albert often disappears for many days at a time; no one knows where he goes. Consuelo follows him but can never find his hiding place until the night she descends into a deep well and finds steps leading to a grotto where Albert and an idiot called Zdenko spend many days together. Zdenko loves Albert more than his own life; when he sees Consuelo coming into the well, he thinks she wants to harm Albert, and he almost kills her. Consuelo escapes from Zdenko and finds Albert. After she speaks soothingly to him, he ceases his mad talk and seems to regain normal behavior. She persuades him to return to his family and not to go back to the grotto without her. Albert tells Consuelo that he loves her and needs her, but, although she no longer loves Anzoleto, she cannot forget how she once loved him, and she asks Albert to wait a while for her answer.

Albert’s father and the rest of the family are grateful to Consuelo for helping restore Albert to his senses. The father, Count Rudolstadt, even tells Consuelo that he will give his consent to a marriage between his son and her, for the old gentleman believes that only Consuelo can keep his son sane. While Consuelo is debating whether she loves Albert and could accept the honor, Anzoleto, deserting Corilla, comes to the castle in search of her. Consuelo slips away from the castle, leaving a note for Albert. She goes to Vienna to rejoin Porpora.

Without funds, Consuelo has great difficulty in reaching Vienna and walks most of the way. In her travels, she meets Joseph Haydn, a young composer who is on his way to the castle to find her; he hopes he can persuade her to take him to...