Scene 1.

Leporello, Don Giovanni’s servant, complains about how difficult it is to have the Don as a master, due to his lustful and devious behavior (for which Leporello is often blamed).  Suddenly, Don Giovanni bursts out of the house of Donna Anna, whom he has just attempted to Rape.  Anna’s father, an aging soldier, challenges Don Giovanni to a duel to avenge his daughter’s honor; Don Giovanni promptly kills him.  Anna’s fiancé, Don Ottavio, tries to comfort her, and Donna Anna makes him swear revenge.

Scene 2.

The next day, Leporello, after making the Don promise not to punish him for speaking his mind, tells Don Giovanni that he leads a scandalous life.  When Don Giovanni becomes angry, Leporello changes the subject and begins discussing women with Don Giovanni.  As the Don tells of his latest flame, Donna Elvira appears.  The men hide as she rages at her betrayal at the hands of a scoundrel.  Don Giovanni, not recognizing her, approaches, thinking her another conquest.  However, she recognizes him as the man who married and abandoned her.  She berates him, and the dismayed Don Giovanni sneaks away.  Leporello stays to explain to her that she is not the only woman to suffer this fate and proceeds to list the Don’s ‘catalogue’ of women to Elvira.

Scene 3.

A group of villagers celebrate the wedding of Zerlina and Masetto.  Don Giovanni and Leporello admire the girls; the Don decides he is exceptionally interested in Zerlina, the bride to be.  He invites everyone to enter his castle to eat, drink and celebrate.  He then attains Zerlina, at the annoyance of a very jealous Masetto.  Don Giovanni promises to marry Zerlina and charms her into becoming his lover.  Donna Elvira reappears, warns the girl, and takes her away, just as Donna Anna and Don Ottavio arrive.  Donna Anna seeks Don Giovanni’s help, not realizing that he is the man who murdered her father.  Donna Elvira returns and tries to tell the others what kind of man the Don really is, but Don Giovanni convinces them that she is mad and takes her away.  However, Donna Anna has realized from his voice that Don Giovanni is her attacker and the murderer of her father.  She tells Don Ottavio what happened to her on the night her father was killed and again begs him to seek revenge.  After the crowd disperses and he is left alone, Ottavio reflects on his love for her. 

Don Giovanni and Leporello reappear, and Leporello tells the Don how he got the villagers drunk and managed to lock Elvira out of the house.  Don Giovanni is pleased with his servant and orders a huge party, then departs to prepare for the celebration.  Masetto storms into the garden, accusing Zerlina of infidelity.  Zerlina begs him to forgive her, telling him he can do anything he wants as long as they can be together.  Masetto relents, but they soon hear Don Giovanni approaching.  Zerlina becomes anxious, which makes Masetto, suspicious, and he hides to watch them together.  The Don renews his attentions and tries to take Zerlina aside, but as they leave, they discover Masetto.  Don Giovanni tries to cover up his intentions, explaining that Zerlina missed her husband and sends the couple off.  Donna Anna, Don Ottavio and Donna Elvira enter in masks for the ball.  Don Giovanni does not recognize them and invites them to the party.  As the guests dance, Don Giovanni continues to court Zerlina.  Leporello grabs Masetto and forces him to dance, so that the Don can dance with Zerlina and drag her away.  Soon, Zerlina’s screams are heard, and Masetto and the others rush to find her.