Act 1
Berlin, 1929

“Willkommen, Bienvenue, Welcome!” With these words the Master of Ceremonies invites us into the excessive, cosmopolitan and free-and-easy world of the legendary Kit Kat Club in Berlin, where the “Golden Twenties” are being celebrated up to the very last minutes of the decade …

Meanwhile, the young American author Clifford Bradshaw is making his way to the capital of the Weimar Republic in order to find inspiration for a new novel. He has been caught in a creative crisis for some time and is travelling to overcome his creative block. In a train he meets a talkative German, Ernst Ludwig, who not only tells him about his business (which includes some minor smuggling operations) and a cheap boarding house run by an acquaintance of his, but also about what he calls the “hottest club in Berlin”, the Kit Kat Club. Having arrived in the city, Clifford seeks out the recommended accommodation and agrees with the widowed owner Fräulein Schneider on a price for a room.

To celebrate the forthcoming New Year, Clifford accompanies his new acquaintance Ernst Ludwig to the Kit Kat Club. The star for New Year’s Eve is the English singer Sally Bowles: a decadent, way-out and likeable artiste. They strike up a conversation and their shared mother tongue becomes a source of erotic stimulus to them. However, the generously dynamic maelstrom of the Kit Kat Club drags Sally back on stage and diverts Clifford into the arms of a former homoerotic acquaintance from London. “Happy New Year!”

A few days later Sally unexpectedly appears at the boarding house and confronts Clifford with her decision to move in with him. Succumbing to her tender urgings and her unique charm, Clifford’s resistance is short lived and he agrees to Sally’s plan. Living together gives rise to an unusual love relationship, and soon Sally is pregnant. In the meantime, Fräulein Schneider is pursuing a heated dispute in the boarding house with her subtenant Fräulein Kost – her objection is the inordinate number of male visitors she has. However, Fräulein Schneider herself is becoming close to another person living in the boarding house – Herr Schultz, a Jewish fruit seller. This results in a hesitant flirtation between two lonely hearts. Both of them are sad to be living alone, and in the context of a “white lie” Herr Schultz announces their engagement. The hope that Fräulein Schneider has secretly nurtured seems to have been fulfilled: full of happiness, she says “yes”!

At the engagement party that takes place shortly afterwards, the mood is lively: Sally has brought along her colleagues and friends from the Kit Kat Club. Drunk with happiness, Herr Schultz sings the Jewish song “Meeskite”, a parable about ugliness and unexpected happiness. When Ernst Ludwig arrives, he not only condemns Herr Schultz’s performance in disgust, but also Fräulein Schneider’s intention of entering into marriage with a Jew. Ernst Ludwig’s political views are becoming obvious, and Fräulein Kost makes a quick decision to join his side. The mood of the party shifts, and the result is an open declaration of commitment to Nazism.

Act 2
Berlin, 1930

Words are quickly followed by deeds: an anti-Semitic act of violence is committed on Herr Schultz’s fruit shop. Fräulein Schneider is forced to acknowledge that in light of political developments, marriage to a Jew would have unavoidably negative consequences, and she breaks off the engagement.

Driven by money worries, Clifford seeks a job in vain and plans to leave Berlin with Sally and her unborn child. With National Socialism on the rise, a future in Germany no longer appears possible to him. However, Sally refuses to recognise this reality and returns to the stage of the Kit Kat Club in spite of her pregnancy. While she sings a bittersweet ode to cabaret, Clifford experiences for himself the violence that is increasingly being unfettered in Berlin, when he is beaten up.Their last meeting takes place the following day in the boarding house: both have been marked by the events of the previous night, Sally having decided to have an abortion. The couple break up: Sally escapes to the Kit Kat Club and Clifford makes his escape from Berlin.

Act I

At the twilight of the Jazz Age in Berlin, the incipient Nazi Party is growing stronger. The Kit Kat Klub is a seedy cabaret—a place of decadent celebration. The club's Master of Ceremonies, or Emcee, together with the cabaret girls and waiters, warm up the audience ("Willkommen"). Meanwhile, a young American writer named Clifford Bradshaw arrives via a railway train in Berlin. He has journeyed to the city to work on a new novel. Cliff encounters Ernst Ludwig, a German smuggler who offers him black market work and recommends a boarding house. At the boarding house, the proprietress Fräulein Schneider offers Cliff a room for one hundred reichsmarks, but he can only pay fifty. After a brief debate, she relents and allows Cliff to live there for fifty marks. Fräulein Schneider observes that she has learned to take whatever life offers ("So What?").

When Cliff visits the Kit Kat Klub, the Emcee introduces an English chanteuse, Sally Bowles, who performs a flirtatious number ("Don't Tell Mama"). Afterward, she asks Cliff to recite poetry for her, and he recites "Casey at the Bat". Cliff offers to escort Sally home, but she says that her boyfriend Max, the club's owner, is too jealous. Sally performs her final number at the Kit Kat Klub aided by a female ensemble of jazz babies ("Mein Herr"). The cabaret ensemble performs a song and dance, calling each other on inter-table phones and inviting each other for dances and drinks ("The Telephone Song").

The next day at the boarding house, Cliff has just finished giving an English lesson to Ernst when Sally arrives. Max has fired her and thrown her out, and now she has no place to live. Sally asks Cliff if she can live in his room. At first he resists, but she convinces him to take her in ("Perfectly Marvelous"). The Emcee and two female companions sing a song ("Two Ladies") that comments on Cliff and Sally's new living arrangement. Herr Schultz, an elderly Jewish fruit-shop owner who lives in the boarding house, gives a pineapple to Fräulein Schneider as a romantic gesture ("It Couldn't Please Me More"). In the Kit Kat Klub, a young waiter starts to sing a song—a patriotic anthem to the Fatherland that slowly descends into a darker, Nazi-inspired marching song—becoming the strident "Tomorrow Belongs to Me". He initially sings a cappella, before the customers and the band join in.

Months later, Cliff and Sally are still living together and have grown intimate. Cliff knows that he is in a "dream", but he enjoys living with Sally too much to come to his senses ("Why Should I Wake Up?"). Sally reveals that she is pregnant, but she does not know who is the father and reluctantly decides to obtain an abortion. Cliff reminds her that it could be his child and tries to convince her to have the baby ("Maybe This Time"). Ernst enters and offers Cliff a chance to earn easy money—picking up a suitcase in Paris and delivering it to his "client" in Berlin. The Emcee comments on this with the song "Sitting Pretty" (or, in later versions, "Money").

Meanwhile, Fräulein Schneider has caught one of her boarders, the prostitute Fräulein Kost, bringing sailors into her room. Fräulein Schneider forbids her from doing so again, but Kost threatens to leave. Kost reveals that she has seen Fräulein Schneider with Herr Schultz in her room. Herr Schultz saves Fräulein Schneider's reputation by telling Fräulein Kost that he and Fräulein Schneider are to be married in three weeks. After Fräulein Kost departs, Fräulein Schneider thanks Herr Schultz for lying to Fräulein Kost. Herr Schultz says that he was serious and proposes to Fräulein Schneider ("Married").

At Fräulein Schneider and Herr Schultz's engagement party, Cliff arrives and delivers the suitcase of contraband to Ernst. A tipsy Schultz sings "Meeskite" ("meeskite", he explains, is Yiddish for ugly or funny-looking), a song with a moral ("Anyone responsible for loveliness, large or small/Is not a meeskite at all"). Afterward, seeking revenge on Fräulein Schneider, Kost tells Ernst, who now sports a Nazi armband, that Schultz is a Jew. Ernst warns Fräulein Schneider that marrying a Jew is unwise. Fräulein Kost and company reprise "Tomorrow Belongs to Me", with more overtly Nazi overtones, as Cliff, Sally, Fräulein Schneider, Herr Schultz, and the Emcee look on.

Act II

The cabaret girls—along with the Emcee in drag—perform a kick line routine which eventually becomes a goose-step. Fräulein Schneider expresses her concerns about her impending nuptials to Herr Schultz, who assures her that everything will be all right ("Married" Reprise). They are interrupted by the crash of a brick being thrown through the glass window of Herr Schultz's fruit shop. Schultz tries to reassure her that it is merely rowdy children making trouble, but Fräulein Schneider is now afraid.

Back at the Kit Kat Klub, the Emcee performs a song-and-dance routine with a woman in a gorilla suit, singing that their love has been met with universal disapproval ("If You Could See Her"). Encouraging the audience to be more open-minded, he defends his ape-woman, concluding with, "if you could see her through my eyes... she wouldn't look Jewish at all." Fräulein Schneider goes to Cliff and Sally's room and returns their engagement present, explaining that her marriage has been called off. When Cliff protests and states that she can't just give up this way, she asks him what other choice she has ("What Would You Do?").

Cliff begs Sally to leave Germany with him so that they can raise their child together in America. Sally protests and claims their sybaritic life in Berlin is wonderful. Cliff urges her to "wake up" and to notice the growing social upheaval around them. Sally retorts that politics have nothing to do with them and returns to the Kit Kat Klub ("I Don't Care Much"). At the club, after another heated argument with Sally, Cliff is accosted by Ernst, who has another delivery job for him. Cliff tries to brush him off, but when Ernst inquires if Cliff's attitude towards him is because of "that Jew at the party", Cliff attacks him—only to be beaten by Ernst's Nazi bodyguards and expelled from the club. On stage, the Emcee introduces Sally, who enters to perform again, singing that "life is a cabaret, old chum," cementing her decision to live in carefree ignorance and freedom ("Cabaret").

The next morning, a bruised Cliff is packing his clothes in his room when Herr Schultz visits. He informs Cliff that he is moving to another boarding house, but he is confident that these difficult times will soon pass. He understands the German people, he declares, because he is a German too. When Sally returns, she announces that she has had an abortion, and Cliff slaps her. He still hopes that she will join him in France, but Sally retorts that she has "always hated Paris." She hopes that, when Cliff finally writes his novel, he will dedicate the work to her. Cliff leaves, heartbroken.

On the railway train to Paris, Cliff begins to compose his novel, reflecting on his experiences: "There was a cabaret, and there was a master of ceremonies ... and there was a city called Berlin, in a country called Germany—and it was the end of the world and I was dancing with Sally Bowles—and we were both fast asleep" ("Willkommen" Reprise). In the Kit Kat Klub, the Emcee welcomes the audience, and the backdrop raises to reveal a white space with the ensemble standing within. The cabaret ensemble reprises "Willkommen", but the song is now harsh and discordant as the Emcee sings, "Auf Wiedersehen... à bientôt..." followed by a crescendo-ing drum roll and a cymbal crash.