Nashville

The overarching plot takes place over five days leading up to a political rally for Replacement Party candidate Hal Phillip Walker, who is never seen throughout the entire movie. The story follows 24 characters roaming around Nashville, in search of some sort of goal through their own (often overlapping) story arcs.
Day One
The film opens with a campaign van for presidential candidate Hal Phillip Walker driving around Nashville as an external loudspeaker blares Walker's folksy political aphorisms, juxtaposed with country superstar Haven Hamilton (Henry Gibson) recording an overblown patriotic song intended to commemorate the upcoming Bicentennial, and growing irritated with the accompanying musicians in the studio. An Englishwoman named Opal (Geraldine Chaplin) who claims to be working on a documentary for the BBC appears in the studio but is told to leave by Haven. Down the hall from Haven's session is Linnea Reese (Lily Tomlin), a white gospel singer recording a song with a black choir.
Later that day, popular country singer Barbara Jean (Ronee Blakley) is returning to Nashville, having recovered from a burn accident, and the elite of Nashville's music scene, including Haven and his companion Lady Pearl (Barbara Baxley), have converged on Berry Field to greet her plane as it arrives. Also present are Pfc. Glenn Kelly (Scott Glenn) and the popular folk trio "Bill, Mary, and Tom" who are in town to record an album. Bill (Allan F. Nicholls) and Mary (Cristina Raines) are married, but largely unhappy, partly due to the fact that Mary is in love with womanizing Tom (Keith Carradine). Meanwhile, Mr. Green (Keenan Wynn) arrives at the airport to pick up his niece, Martha (Shelley Duvall), aka "L.A. Joan," a teenage groupie who has come to Nashville ostensibly to visit her aunt Esther Green who is sick in the hospital. However, Martha repeatedly puts off visiting her aunt in favor of chasing after male musicians. Working at the airport restaurant are African-American cook Wade Cooley (Robert DoQui), and his pretty waitress friend, Sueleen Gay (Gwen Welles), an aspiring country singer who refuses to recognize that she can't carry a tune.
After greeting the crowds on the tarmac, Barbara Jean faints due to the heat, and her handlers, headed by her domineering husband-manager Barnett (Allen Garfield), rush her to the hospital. Barbara Jean's appearance having been cut short, those in attendance depart the airport and wind up stranded on the highway after a pile-up occurs. During the commotion, Winifred (Barbara Harris), an aspiring country singer, runs away from her husband, Star (Bert Remsen), after he refuses to take her to the Grand Ole Opry. Star gives a ride to Kenny Frasier (David Hayward), who has just arrived in town carrying a violin case. Opal takes advantage of the traffic jam to interview first Linnea and then Tommy Brown (Timmy Brown), an African-American country singer who is performing at the Opry. Tommy and his entourage go to Lady Pearl's club but Wade, who is drinking and trying to pick up white girls at the bar, insults Tommy for being too "white" and starts a fight.
Linnea's husband, Del Reese (Ned Beatty) is working with political organizer, John Triplette (Michael Murphy) to plan a small fundraiser and a large outdoor concert gala for the Walker campaign. Sueleen appears at a local club's open mike night in a provocative outfit, and despite her lack of singing ability, club manager Trout (Merle Kilgore) recommends her to Triplette for the fundraiser based on her appearance. Winifred shows up at Trout's club trying to recruit musicians to record a demo with her, but Star sees her and chases her out. Del invites Triplette for family dinner with Linnea and their two deaf children. Linnea and Del are having communication problems and she focuses on the children rather than on him. In the middle of dinner, Tom calls trying to make a date with Linnea, but she puts him off, so he takes Opal back to his room instead. Pfc. Kelly sneaks into Barbara Jean's hospital room and sits in the chair by her bed all night, watching her sleep.
Day Two
Tom calls Linnea again but, with Del listening on the other line, Linnea yells at Tom and tells him not to call her any more. Kenny rents a room from Mr. Green. Haven throws a pre-show party at his house before the evening's Grand Ole Opry performance. At the party, Triplette tries to persuade Haven to perform at the Walker gala by telling him that if Walker is elected, Walker would back Haven for state governor. Haven says he'll give Triplette his decision after the Opry show that night.
Later, Tommy Brown, Haven, and Connie White (Karen Black) all perform at the Opry. Connie is substituting for the hospitalized Barbara Jean. Winifred tries unsuccessfully to get backstage. At the hospital, Barbara Jean and Barnett have an argument because he is going to the after-show gathering to thank Connie for substituting at the last minute. Barbara Jean doesn't want him to go and he accuses her of having another nervous breakdown like she did previously. Barnett finally subdues Barbara Jean and leaves, but Connie doesn't seem happy to see him. Haven tells Triplette that Barbara Jean and Connie never appear on the same stage, and that he (Haven) will appear anyplace Barbara Jean also appears. Bill gets upset when his wife Mary doesn't show up all evening; she is sleeping with Tom.
Day Three
It is Sunday morning and the characters are shown attending various local church services. A Roman Catholic service includes Lady Pearl, Wade and Sueleen in attendance; Haven sings in the choir at a Protestant service; and Linnea is seen in the choir at a black Protestant church as a baptism is taking place. At the hospital chapel, Barbara Jean sings "In the Garden" from her wheelchair while Mr. Green and Pfc. Kelly, among others, watch. Mr. Green tells Kelly how he and his wife lost their son in WWII. Opal wanders alone through a huge auto scrapyard making free-form poetic speeches about the cars into her tape recorder. Haven, Tommy Brown and their families attend the stock car races, where Winifred also attempts to sing on a small stage but cannot be heard. Bill and Mary argue in their hotel room and are interrupted by Triplette, who wants to recruit them for the Walker concert gala. Tom tries to get chauffeur Norman (David Arkin) to score him some pills.
Day Four
Opal walks alone through a large school bus parking lot making more strange observations into her tape recorder. Barbara Jean is discharged from the hospital at the same time Mr. Green shows up to visit his sick wife. Barbara Jean asks after his wife and sends her regards. After Barbara Jean and her entourage have left, a nurse tells Mr. Green his wife died earlier that morning. Back at Mr. Green's house, Kenny gets upset when Martha tries to look at his violin case.
Barbara Jean performs at Opryland USA. Triplette and Del attend and try to convince Barnett to have Barbara Jean play the Walker concert gala at the Parthenon the next day, but he refuses. Barbara Jean gets through the first couple of songs all right, but then begins to tell rambling stories about her childhood instead of starting the next song. After several false starts, Barnett escorts her from the stage and tells the disappointed audience that they can come to the Parthenon tomorrow and see Barbara Jean perform for free, thus committing her to the Walker concert.
Tom calls Linnea and invites her to meet him that night at a club where he is playing. Linnea arrives but sits by herself because Martha is trying to pick Tom up. Mary and Bill are also there, and Opal sits with them and talks about how she slept with Tom, causing Mary to become upset. Wade tries unsuccessfully to pick up Linnea, while Norman tries equally unsuccessfully to pick up Opal. Tom sings "I'm Easy" and Linnea, moved, goes back to his room where they make love. When Linnea needs to leave, Tom calls another woman and has a romantic conversation within Linnea's earshot while she is getting dressed.
Sueleen appears at the all-male Walker fundraiser, but is booed off the stage when she sings poorly and doesn't take off her clothes. Del and Triplette explain that the men expect her to strip and that if she does so, they will let her sing the next day at the Parthenon with Barbara Jean. Sueleen is visibly upset but strips anyway. Winifred shows up at the fundraiser hoping to get a chance to sing, but after she sees what is going on, she stays hidden behind a curtain. Del drives Sueleen home and drunkenly comes on to her, but she is rescued by Wade. After he hears what happened, Wade tells Sueleen she can't sing and asks her to go back to Detroit with him the next day. Sueleen refuses because she is determined to sing at the Parthenon with Barbara Jean.
Day Five
The performers, audience and Walker and his entourage arrive for the Parthenon concert. In the performing lineup are Haven, Barbara Jean, Linnea and her choir, Bill, Mary and Tom, Sueleen, and Winifred who has shown up again hoping for a chance to sing. Barnett gets upset because Barbara Jean will have to perform in front of a large Walker advertisement, but has to go along with it because his wife's career will be harmed if he pulls her out of the show. Mr. Green and Kenny attend Esther Green's burial service and Mr. Green leaves angrily, vowing to find Martha (who is not at the service) and make her show some respect to her aunt. Mr. Green and Kenny go to the Parthenon to look for Martha.
The Walker gala starts and Haven and Barbara Jean perform a song together, then Barbara Jean sings a solo song. At the end of the song, Kenny takes a gun from his violin case and shoots Haven and Barbara Jean. Pfc. Kelly disarms Kenny as chaos breaks out. Barbara Jean is carried bleeding and unconscious from the stage. Haven tries to calm the crowd by exhorting them to sing, asserting that "This isn't Dallas". As he is led from the stage for treatment of his wounds, he hands the microphone off to Winifred, who begins to sing "It Don't Worry Me" and is joined by Linnea's gospel choir. The film ends with the audience raptly listening to Winifred's song â she has finally gotten her big break.

Question: Who did Barbara Jean have an argument with?
Answer: Barnett