Royal Wedding (1951)

In director Stanley Donen's romantic musical (in his first solo directorial assignment and his second film) - loosely based on Fred Astaire's early dance career with his own sister Adele (for almost three decades, beginning in the early 1900s) - with Astaire and Jane Powell (as Tom and Ellen Bowen) - a famed sister/brother dance/song team and act on Broadway (in a smash hit revue show titled Every Nite at Seven at the 49th St. Theatre) - featuring some of the most creative dance acts in film history:

• the Broadway musical production's opening number: "Every Nite at Seven" - a "play within a play" by the film's two main characters: brother and sister act Tom Bowen (Fred Astaire) portraying a bored crowned king and his sister Ellen Bowen (Jane Powell) as his flirtatious pretty maid
• after the closing of their long-running NYC show, their agent Irving Klinger (and his twin brother Edgar in London - both Keenan Wynn in a dual role) had booked them overseas; Tom and Ellen were to take their show to London's Mayfair Theatre, to cash in on a 'Royal Wedding" and its festive crowds - the marriage (scheduled in one month) of Princess Elizabeth II to Prince Philip Mountbatten, the Duke of Edinburgh, in 1947 (an actual historical event that occurred on Nov. 20, 1947)
• they were to depart on a French Trans-Atlantic ship to London; at the dock as they left, Ellen said goodbye to two competing boyfriends: Billy (John Hedloe) and Pete Cumberly (John R. Reilly), they waved at her and then engaged in a fight; as she was boarding, she had her first glimpse of a womanizing Englishman who was saying a heartfelt goodbye to two different women; he winked at her - she was unaware that he would become her future love interest
• both would soon find romance during their sojourn - Ellen was the first to fall in love on board the ship in the letter-writing room, with secretly-poor English aristocrat Lord John Brindale (Peter Lawford) - a socially-connected gentleman (later Tom noted how she had fallen hard for him: "He didn't have to chase very hard after her. She stood still and waited")
• in an incredible and inventive practice dance number titled "Sunday Jumps" (a hat and coat stand-rack routine), Tom was forced to dance solo (Ellen missed her 2 pm rehearsal time with him) to a metronome beat with a clothes-horse (or hatstand-rack) and gym equipment in the ship's workout room; inserted into the dance was a body-building segment, using wall-mounted weights, parallel bars, a pummel horse, and a suspended boxing bag, to mock and parody his muscle-bound dancing rival/friend Gene Kelly; when finished, he bowed to an imagined audience
• during the song-dance number "Open Your Eyes" set in the ship's ballroom during a gala benefit show, rough weather caused the two dancers (Ellen in a sparkly lilac-colored dress with a red sash and Tom in a tuxedo) to slip and slide on the seesawing, rocking dance floor
• the sequence of Tom's discovery of romance with Anne Ashmond (actress Sarah Churchill, Winston's daughter!, in her American film debut); he first met her on a London street and then realized she was one of his aspiring, auditioning dancers for his show - and he chose her on the spot; he learned that she was the daughter of Cockney, Yankee-hating pub landlord James Ashmond (Albert Sharpe); she claimed she was already engaged to Chicago area-dwelling American Hal Rayton, who worked in the luggage department at Olgivy's department store
• both Tom and Ellen feigned tiredness, but then snuck out of their hotel rooms for dinner and a night on the town with each of their newfound partners - they caught sight of each other leaving the hotel, smiled and realized their mutual ploys

Romance in London
To the Countryside - Ellen With Lord John Brindale	Tom Meeting Anne on Street	Anne - One of Tom's Auditioning Dancers
Dinner Between Tom and Anne	Tom and Ellen Bowen in London	Ellen Seriously in Love with Lord Brindale

• on opening night in London, Tom and Ellen's comic, vaudeville-like, slightly vulgar song-dance (with Brooklyn-accents) to the impossibly-titled "How Could You Believe Me When I Said I Love You When You Know I've Been A Liar All My Life" - [Note: It was noted as the longest title of any song in an MGM musical]
• the amazing, most spectacular song and dance scene ever created (a "wall and ceiling walk") - after being lovestruck by Anne but forlorn, Tom Bowen sang to her photograph, and then solo tap-danced energetically in the number "You're All The World To Me" on the walls and ceiling of his London hotel room
  [Note: the set - his hotel room - was devised as a rotating cube that rotated at the same speed as the strapped-down camera.]

Tom Dancing on His Hotel Room Walls: "You're All the World to Me"

• the sultry performance of the two star dancers wearing colorful costumes (Tom was clad in a yellow suit and tie with pink shirt, and Ellen in a bright blue outfit with green waist-sash and headdress) in a lavish Latin American or Caribbean production number to the tune of "I Left My Hat in Haiti"
• after an investigation, it was discovered that Anne's fiancee Hal Rayton in Evanston, IL had married a few months ago - so Anne's long-standing engagement was called off, and she was free to be with Tom; she responded with a surprised reaction: "How wonderful, how simply wonderful" but he was unsure of marriage and feared being a failure: "I know I'd be an awful flop as a husband"
• by film's end, Tom and Ellen had resolved to not marry their respective partners and stay together as a team-act - (Ellen: "How can you even consider breaking it up? And breaking it up for what? To get married"; Tom was coerced to agree: "It's you and me, just like it's always been"); but then while viewing the jubilation of the royal wedding parade, they changed their minds; bursting with excitement, they told Edgar: "We want to get married" - and he replied: "I thought you two were related!"
• after pulling strings to hastily get a marriage license, the film concluded with the aftermath of a double-marriage ceremony that afternoon at 4 pm at the Clyde Street Church between Tom and Anne, and Ellen with Lord Brindale - the two couples emerged from the church, where Tom quipped: "They didn't have to go to all this trouble. A small wedding would've been all right"