Act One

George, a brooding artist, enters a framed but otherwise empty white space. He sits at an easel with a drawing pad and a box of chalk. As he addresses the audience, the scene transforms into a grassy-green expanse of park. The sun rises as the cut-out form of a couple appears. It is the island of La Grande Jatte in the middle of the River Seine, and it is 1884 Paris. Dot, George's mistress and model, enters in elaborate, bustled dress. Georges turns her profile towards the audience and begins to sketch her. She fidgets and complains about being uncomfortable. She obviously wants George to pay attention to her, but he is absorbed only in his painting ("Sunday in the Park with George"). As George continues to give Dot orders and treat her like an inanimate object, other characters appear, including an old lady and her nurse. George observes and paints the other characters, trying to get everything just right. Through snippets of conversation, the audience learns information that helps to establish time and place for the painting – for example, the Eiffel Tower is being constructed in the distance.

Another artist, Jules, and his wife, Yvonne, enter and view George's composition. They criticize his vision, displeased with what they see ("No Life"). Jules and Yvonne visit George in the park. They exchange idle chatter, avoiding real comment on George's work. They leave, and Dot expresses her disdain for them. George sends Dot off, pleasing her by telling her that they will go to the Follies later. He attempts to draw the old lady's picture, and we learn that she is his mother, but she does not appear to recognize him.

George and Dot are in his studio. While Dot is musing to herself that George paints all night while she dreams, George works alone on the huge canvas. As George struggles to get every aspect of his work just right, Dot dreams of being in the Follies ("Color and Light"). George takes a moment away from the painting and tells Dot that he can't go to the Follies tonight, because he has to work on the painting. She stalks out.

On another Sunday in the park, George sketches a boatman with his black dog. Two girls named Celeste #1 and Celeste #2 are now in the painting. As George talks with the boatman, Dot passes through the scene with Louis the Baker. The women onstage gossip about the fact that Dot has obviously taken up with another man and remark on George's recent affair with numerous women ("Gossip"). Jules and Yvonne appear, and Jules says that there is talk of including George's paintings in an important group show, but they are not pleased with this idea. Dot studies her reading lesson. The Boatman speaks gruffly to Louise, Jules and Yvonne's little girl. George corrects him. Enraged, the boatman leaves.

George proceeds to sketch the dog. George speaks to Dot, who has moved out of his studio. Louis appears with a treat that he has baked for Dot. George steps away quickly. Dot and Louis leave. George sits down and resumes his painting of the dog; George imagines everyone's thoughts in the park ("The Day Off"). Jules and George discuss George's work. Jules tells George to forget experimentation and to spend his time meeting prospective buyers, enjoying life instead. The Boatmen tells George that artists can't really know the people whom they paint. He accuses George of painting what is true with one eye and what suits him with the other. Dot enters and explains that she has met a good man – Louis. He is not what she had in mind, but she is choosing him because it seems as though she cannot have George... and she needs someone ("Everybody Loves Louis"). Mr. and Mrs., two American tourists, appear with pastries. They decide that they will take a baker home with them. The two girls named Celeste begin fishing. They soon attract the attention of two soldiers; one of whom is represented by a cardboard cutout.

George sits at his easel, painting and reflecting on Dot's decision to leave him. He thinks about the fact that while the world experiences life, he sits and watches, as he tries to capture it in his paintings. He realizes that he can never completely give himself over to a relationship without having his art get in the way ("Finishing the Hat"). Dot comes to George's studio, pregnant with George's child. She asks George for the painting that he made of her powdering herself. She is planning to marry Louis. Jules and Yvonne arrive. As George and Jules look at George's work, Yvonne and Dot, who have always had little use for one another, converse about their respective situations. George attempts to excite Jules about his revolutionary use of color. He has painted in red and blue, yet the eye perceives violet. Jules accuses him of trying to be a scientist instead of a painter. Jules says that he knows George wants to be included in the next group show. He says, reluctantly, that he will consider speaking on George's behalf.

Disappointed, Jules has not immediately seen the merit in his work, George forgets that Dot is waiting in the next room for him, until she reappears. She tells him that she and Louis are going to America. He says that she will not like it there and returns to his painting. She is outraged at how little he seems to care; she implores him to ask her to stay, but he cannot do that ("We Do Not Belong Together"). George goes back to the island one more time and draws the old lady in the park. She now seems loving and warm towards him. They share sweet, but contradictory, memories they each see their shared past differently. She longs for all of the things that are disappearing from the landscape of her life, and he tries to capture the existing world on his canvas ("Beautiful").

Louis and Dot, who carries her baby, Marie, enter. Dot brings Marie to George. She again asks for the painting that he did of her. He says that he has repainted it with another model. He refuses to look at his child, saying that Marie now belongs to Louis. Dot starts to leave, unable to speak. Georges says that he is sorry, and Dot and Louis exit. George's mother says that she has worried about him all of his life. She urges him to connect with people. Jules and Frieda appear, looking for a spot in the park where they can share a stolen moment of passion. The two Celestes and the two soldiers appear and begin to fight about their coupling. Yvonne finds Louise, who reports that she discovered her father and Frieda together. Yvonne accuses Jules of being unfaithful with Frieda. A fight ensues between Jules, Yvonne, Franz and Frieda.

Soon, the entire stage is filled with fighting. George freezes everyone, and the noise ceases. Everyone begins to take positions around the stage at his direction. They create the picture that we know as A Sunday Afternoon on the Island of La Grande Jatte. The company describes the world inside of the picture ("Sunday"). George rushes about making small adjustments. On the final chord, the completed canvas flies in on a painted scrim. The lights go down slowly as the image of the characters fades behind the painting, with George standing in front.

Act Two

We return to the entire company onstage in the painting, as we left them. They give a tense review of the miseries that they are each experiencing, frozen in position on a canvas ("It's Hot up Here"). They leave the stage one by one, exchanging their reactions to George's sudden death.

The lights change, and we are now in 1984, in the gallery at the museum where George's painting now hangs. A contemporary artist, George enters pushing Marie, his grandmother, in a wheelchair. Dennis, George's technical assistant, pushes in a control console. George of 1984 is an inventor-sculptor. He introduces his post-modern invention, a large contraption entitled Chromolume #7. George explains that he has been commissioned to do this work in commemoration of Georges Seurat's painting. George and Marie review the history of Georges Seurat ("Chromolume #7"). Then, Chromolume #7 is activated. Music swells. Brilliant shafts of light appear. Colors fill the stage, creating a pointillist effect. The machine begins to produce images from the painting... when it suddenly explodes. George apologetically explains that there is an electrical problem. Marie reveals that she believes Seurat to be her real father, though George disputes this idea. She displays the small red book that Dot used to write in as proof. The Chromolume sends laser beams bursting throughout the theatre.

The painting flies in. We are at the museum reception honoring George. The guests argue among themselves about the validity of the Chromolume as art. George networks with the crowd ("Putting It Together"). He appears to excel at the part of being an artist that his great-grandfather did very poorly. As he moves from one group to another, he replaces himself with a cut-out likeness.

George's former wife, Elaine, appears at Marie's side. Marie tells some of the guests that she and George have planned a trip to France, where he will do a presentation on La Grande Jatte with the Chromolume. The art critic, Blair Daniels, begins to lecture George about his lack of originality and failure to move beyond the Chromolume concept. Blair and Marie talk about the Seurat painting. Marie tells Blair that there are only two things in life that are worthwhile to leave behind: children and art. Elaine tells George that she thinks that Marie is tiring and will take her to the hotel. They embrace fondly. Marie continues stressing the importance of family ("Children and Art"). When Marie and Elaine leave, George urges himself to connect.

George and Dennis are on the Island of La Grande Jatte. It is now covered with high-rise buildings. A tree that George originally removed in Act 1 and then reinserted into his painting is all that remains of the old landscape. As they discuss the installation of the Chromolume, Dennis says that he is quitting his work with George, because he wants to do something new. George says that he, too, needs that in his life; he wants to create art that means something to him. We learn that Marie has died and that George has brought her red book with him. Dennis leaves, and George begins to read the notes in the back of the book. Dot's notes move him to take stock of his own life ("Lesson #8"). Dot appears and sees George reading her book. She speaks to him as if he were the other George. She thanks him for all that he tried to teach her and asks him about his work. He tells her that he has nothing to say in his work, and she tells him that he has to stop blocking himself ("Move On"). Suddenly, Dot and George are singing together, completing the love song that they were never able to finish in Act I.

Dot gives George of 1984 the power of his great-grandfather to explore his own vision. The old lady appears and asks George if the island is what he expected. He replies that the air is rich and full of light. The old lady leaves, and George begins to recite his great-grandfather's words about art. The characters from the original painting stroll in among the new buildings that represent the present. They stroll off. Dot leaves as a blank, white canvas descends. George repeats his grandfather's sentiment from the beginning of the show – a blank canvas represents so many possibilities ("Sunday").