an Old-Fashioned Girl": Caulfield sings this number, specially written for the film. "Puttin' on the Ritz": Although Berlin's 1930 song was originally written for vaudevillian Harry Richman, it has become indelibly associated with Astaire, who also recorded it for Columbia in 1930. In this tap solo with cane, which was widely billed as "Astaire's last dance", the lyrics are updated, replacing references to ritzy Harlemites with wealthy whites strutting their stuff up and down Park Avenue. The routine was produced after the rest of the film had been completed, and according to Astaire, it took "five weeks of back-breaking physical work" to prepare. It is constructed in three sections, beginning in a book-lined office with Astaire dressed in a morning suit. Here Astaire delivers the song while executing a gentle tap and cane solo in mock slow-motion, in an amusing parody of his impending retirement. The song finished, he returns to dancing at normal speed and dances around the office while executing an ingenious jumping cane routine, which relied on a concealed floor trigger mechanism. Rejuvenated, Astaire sweeps aside a pair of drab curtains to reveal a chorus of nine Fred Astaires – achieved by filming two separate versions of Astaire, repeating them four times and interleaving them. The final section of the number is a repeat of the tune with a greatly reduced tempo, which accompanies a complex routine for Astaire and chorus. In "Top Hat, White Tie and Tails" from Top Hat (1935), Astaire pretended to machine-gun his chorus dancers with his cane and loud taps. This time, Astaire joins his chorus in adopting a confrontational, at times almost menacing posture towards his audience. In 1957, on the brink of yet another temporary retirement, Astaire wittily refers back to this routine in the self-parodying "The Ritz, Roll And Rock" number from Silk Stockings. "(I'll See You In) C-U-B-A": A 1920 song performed as a duet by Crosby and San Juan. "A Couple of Song and Dance Men": A comic song and dance duet for Astaire and Crosby to a number specially composed for the film. The concept is a reworking of the "I'll Capture Your Heart" number from Holiday Inn (1942) and the comedy centres on Crosby's legendary reluctance to rehearse. "You Keep Coming Back Like a Song": Crosby performs this specially composed number. "Blue Skies": Crosby sings this 1926 ballad, the film's title song, to Caulfield. "Nightclub