The opening scene takes place at a rock concert. The audience is getting restless, and even a child has got lost. Somebody throws some fireworks at other people and a fight breaks out. Finally, the star arrives on stage, but he is drunk. He sings one song and gets halfway through the second one when he forgets the lyrics of it completely. John Norman Howard (Kris Kristofferson) insults the audience, and then walks off the stage leaving behind only mayhem.
His entourage gets frantic at him as they leave in the car. They, including Bobbie Ritchie (Gary Busey) are worried because John's attitude is horrible. One of his band members offers him some adrenaline smuggled out of a hospital by somebody she knows. Another tries to convince him to sleep for a while, as the concert of the following day is really important. However, John insists on going out somewhere.
He is taken to a bar where Esther Hoffman (Barbra Streisand) is singing her own songs. John has taken a bottle of whiskey with him but the bar is unlicensed and only tea, coffee or herbal tea is available to buy and the waitress tries to get John to give her the alcohol to look after until he leaves but John insists on keeping the bottle with him. Finally, Esther steps in the conversation and allows him to drink it as long as he doesn't make a scene while she is singing. John Howard gets mesmerized by Esther.
Soon after, a couple of John's friends find him in the bar and talks loudly over the singing even though John asks him not to. The two then end up in a fight and Esther and her backing singers take cover as the situation disintegrates. The bar owner manages to break up the fight and announces they are closing right now. Esther grabs John by the hand and helps him escape the crowd by ducking out of a back door and they get into John's car.
Arrived at Esther's, he wants to come in but she says no and invites him to come back for breakfast, which he does. Over breakfast, he invites her to a concert that afternoon and she agrees to go. She travels there with him in his helicopter.
At the concert, he starts singing and suddenly gets the idea of making her sing onstage. Esther runs backstage and John follows her. A male fan kisses John - who doesn't make a show out of it, but says that he doesn't like the fan, but his motorbike. The crazed fan gives him his motorbike. John jumps on the bike and starts riding around rather wildly, including going up on stage and doing 'donuts'. Unfortunately, he fails to realise he has snagged a cable, loses control of the bike and ends up going off the front of the stage taking a lot of speakers with him. The audience is getting mad at him, a riot is begun, John is taken away by ambulance and all his entourage leave in the helicopter, everyone forgetting Esther and leaving her all on her own among the ruins.
After a relatively unhurt John is released from hospital, a radio DJ called Bebe Jesus (M.G. Kelly) hovers in a helicopter over the swimming pool and invites John to his studio. John shoots the helicopter, so Bebe Jesus promises not to play any of John's songs in the future, and never to say his name again. Days later, when John goes with a box of beer bottles to make peace with Bebe Jesus, the radio disk jockey puts him to shame in front of his live audience over his alcoholism.
John is angry because Esther has not tried to get in touch with him. He asks one of his entourage if they tried her home and they say she wasn't home. When he does manage to find her, it turns out she tried calling him but three times the phone wasn't answered and the fourth time she heard a message saying the phone was disconnected. John thinks about it and tells her it would have been because his phone number is changed every six weeks to keep calls from fans in the middle of the night to a minimum because they keep finding out his number.
John takes Esther to his mansion. He is a lone bear who likes spraying graffiti on the walls. He writes her name on the wall. There, they make love, have a bath together, and he listens to her ad-libbing on his piano. She thinks no one would be able to sing to the tune she has made up but he comes up with some lyrics on the spot and starts singing along to the music.
Little by little, he starts to admire and encourage her. He even lends his music band and studio time for her to record her own materials with her voice. One of the music producers complains that John hasn't recorded any new songs for a long time. The producer tells him that the musicians are good, but they don't fit Esther's music, style or voice. John disagrees but Esther steps in and changes some of the music to make it her own.
John's manager Brian (Paul Mazursky) has signed him for a charity concert in favor of the American Indians. John doesn't want to do it but he is finally convinced as he needs to satisfy his public just this once, a concert which is supposed to go smoothly for once. When the day of the concert arrives, there is a huge crowd as usual. On the concert, John stops singing, stops the musicians, and tells the audience about a discovery of his.
Esther is forced to sing two of her songs. Although the audience hates her looks at the beginning, they wildly cheer at her afterwards.
Suddenly, John's manager wants to sign her. The music radio journalist wants to talk to him. John takes off in his flashy car.
John tells her that she's succeeded, but she tells him that she wants to get married to him. John tells her that she doesn't really need him but she persists. They get married in a rushed civil union. John takes Esther to a plot of land he has, but there is no home on it.
They start working on the site to build their mansion. She wants to have a tour co-starring with him, but he thinks that she should do the tour on her own. She feels insecure and asks him to go with him. He gets angry, because he doesn't want to go with her. She threatens him with staying at home and being only a wife. He leaves the home and creates more mayhem on his motorbikes. He jumps from some plank-boards and lands on the floor... without the motorbike. She runs to take care of him, but nothing the matter happened to him. She tells him that she won't be able to have children with him because he only does crazy things. She mentions that she doesn't like men with beards, so he tries to cut his. Esther won't let him.
Brian arrives with a photographer (Sally Kirkland). Brian thinks that the bad publicity surrounding John would taint Esther's tour and that John should stay at home while she goes on tour. Brian tells John and John tells Esther while a photographer takes pictures of her.
John finally accompanies her, but his idea of creating a new music band with his studio musicians called Freeway, but the idea seems to fall apart. Esther career takes off and stays up high.
One evening John visits his musicians. The musicians are practicing. One of them (Stephen Bruton) tells John that the group is now called Speedway, that they are going solo and that they're having quite a success. After all, they had to do something while John was frolicking with Esther in the middle of their isolated mansion. John makes up a story and says that he has different plans: to go on a tour on his own, with only two musicians he found in a town bar.
John is sad and begins to sing to the sound of his guitar. He is interrupted by the phone. He picks it up: the voice is asking for Esther, wants to talk to her and asks him whether he is his secretary. John doesn't pick the phone anymore. John tells Esther - when she arrives after another successful gig - that many people are looking for her. She asks him what happened to his idea of going on tour with his old band, but John doesn't want to talk about it, and goes to drink some more.
The Grammy Awards: John is not there with Esther. Esther wants to leave, but Brian and Freddie Lowenstine (Joanne Linville) stops her. Esther wins the award for Best Female Singer. While she is giving her acceptance speech, John arrives completely drunk and makes a scene. Esther thanks two people for her success - one of them is John. John feels outraged, so he says that Esther doesn't owe anything anybody.
Esther and John leave. They practically run away. The journalists runs after them. They fall down to the floor, and John punches one of the journalists who asks him if he has resorted to violence with his wife. Esther is outraged at the photography and gossip-seeking and tries to stop it, then helps John up and leaves with him.
Esther's success goes on. She goes on tour, this time on her own. Brian is her manager as well. Once, while she is being hurried on by the light technicians and there are problems with the synch of singing and the descent of some stairs, she tries to talk to Brian. John is writing songs again, many of them, but in a different way. Brian finally agrees to give John a last chance. After all, and although he doesn't want to admit it, he appreciates him. Brian feels that he can't save John no matter what he does. Brian calls on John and listens to the songs, and doesn't like them. John notices that. Brian tells him that these songs are different to what he used to do, but that he would like to have them recorded anyway. However, John's intuition tells him what's going on and he says that he is going to record those songs with other musicians and producers.
John leaves for his mansion, all on his own. However, he finds a "squatter". Quentin (Marta Heflin) is swimming half-naked on his swimming-pool. John is rude to Quentin. He wants her to go away. She writes for Rolling Stone and other magazines. She says she would do anything to get an exclusive interview... with Esther! When Esther arrives soon after, she finds both of them in bed. They talk of the interview nonchalantly, and Quentin questions Esther, who stays motion- and speechless. John tells Quentin to get the hell out, and she does so in anger, saying that he was a crappy lover. Esther leaves the bedroom and smashes some vases and all the bottles of alcohol of John. She slaps him but John doesn't defend himself. She doesn't want to destroy her life like he has destroyed his.
In spite of his anger, Esther can't leave him when he tells her that Quentin didn't really matter at all. They go to their small home in the middle of nowhere.
One day, John goes alone to the airport to pick someone up and bring them back. He takes his flashy sports car, puts on some of Esther's songs and drives fast and recklessly, failing to properly heed the warning signs on the road.
A helicopter in the middle of nowhere. The red sports car has had an accident. John is dead. Esther runs to him but it's useless. Esther asks for a blanket. She cries in silence. She wonders what she would do without him. He is taken away in an ambulance.
Back at that huge mansion John had bought, Esther is alone, staring at the wall, still struggling to accept that John is dead. She runs downstairs when she hears John's voice. John is calling out, demanding someone else answer the phone. A mover comes from another part of the house asking if she knows how to turn off the tape recorder that's playing an old recording session of John's, during which the phone had started ringing.
The DJ who wouldn't accept John's apology, is heard on the radio saying that John was one of the greats.
At Esther's next concert, as she steps up to the microphone and the lights are dimmed, the entire audience quietly raises candles as tribute to her lost husband. Touched, Esther softly begins singing one of John's trademark songs that his group performed early in the film, but as a ballad rather than a rock song. It gradually leads into more powerful singing, all of it focusing on their love, the impact he had on her life and the effect on her of his loss.