A great aid in following along with the action is a relationship flowchart. This is a good summary of the basic story I found from Ryan Ozawa.
1961 -- Prologue: "Love Changes Everything." Alex recalls the events then recounted in the play. 1947 -- Rose and company close a terribly-recieved Ibsen play in France. Alex, a star-struck teen, follows her to a cafe ("Parlez Vous Francais") and invites her to run off with him. On a whim, she agrees. They board a train ("Seeing is Believing") for Pau, where Alex's uncle -- George -- has a villa. They break in and 'live in sin.' George at the time is in Paris with fellow artist Giulietta. He recieves word of his nephews antics and departs to Pau to investigate ("A Memory of a Happy Moment"). George arrives and crashes Alex's love-in. They tour the house, and George woos Rose with his exploits. While George and Alex argue about what's going on, Rose sneaks off and dresses in the gown once worn by George's late wife, Delia. He nearly faints... He agrees to leave. Soon after ("Chanson D'Enfance") Rose recieves word that Marcel (her director) needs her for the next opening of their play. She departs. 1949 -- Two years later, and Alex has joined the army. During a leave, ("Everybody Loves a Hero") he lands in Paris and decides to visit his uncle George. Upon arriving at his flat, however, Alex finds Rose there. She's been living with George for some time, and is in love with him although he's never proposed... Next thing you know, Alex and Rose hop in the sack again. The next morning, Rose is aloof and asks Alex to leave. He loses his temper and shoots Rose in the arm. George arrives and renders aid... Alex and George then argue like "gentleman" over who'd be better for Rose ("She'd Be Far Better off With You"). George leaves of his own accord for Venice. Rose isn't too enamoured with the arrangement, however, and has Alex kicked out by Marcel. She then runs off to Venice, to meet the famous Giulietta. George recounts his experiences with Rose to Giulietta, who consoles him ("Stop, Wait, Please..."). Suddenly, Rose arrives with Marcel, frantic and in debt. Giulietta and George take her in. Rose and Giulietta become fast friends, trading tales of George's peculiarities. By the end of the scene, the two hop into bed. It's revealed that George is in financial dire straits, but even so he proposes to Rose. She agrees. They are married... meanwhile, Alex is at a military camp in the Malayan Jungle, where he recieves news of their marriage. 1962 -- Thirteen years later (Act Two). Rose is again closing up a show in Paris, and is now a resounding success ("Leading Lady"). Alex arrives again at the show, older and more mature. She invites him along on her break to visit with her husband George and daughter Jenny. George and Jenny, while Rose is frequently away performing, live a good life ("Other Pleasures"). Rose arrives with Alex in tow, and they are reunited -- Rose recieves word that Giulietta won't be able to visit as promised ("There is More to Love"), having more problems with relationships. 1964 -- Alex arrives again for a party, and in the meantime begins to bond with Jenny ("The Mermaid Song"). The party comes, and George and Jenny have a dance ("The First Man You Remember"). Then Alex has a dance with her, after which Jenny becomes duly enamoured of him. Rose warns both Alex and George of her misgivings of Jenny's affections, but they continue nonetheless. Meanwhile, George begins obsessive plans for his funeral... George, suspicious, charges to her room to confront them. How- The family takes a trip to a carnival ("The Journey of a Lifetime"). Alex and Jenny become a tad to affectionate in front of George, and he storms off. Alex, Jenny, Rose and George consider the madness of their situation ("Falling"). That night George puts Jenny to sleep, and Alex sneaks in later to be with her. George, suspicious, charges to her room to confront them. How- ever, on the way suffers a heart attack and dies outside her door. George's funeral takes place ("Hand me the Wine and the Dice"). Giulietta arrives and seduces Alex. She convinces him to stop affairs with Jenny. Jenny becomes frantic and proposes. Suddenly Rose arrives and laments her loneliness ("Anything but Lonely"), and asks him not to leave.