One of only four Fred Astaire musicals in which his female co-star received top billing above him, the others being Paulette Goddard in Second Chorus (1940), Judy Garland in Easter Parade (1948) and Audrey Hepburn in Funny Face (1957). In each case, the actress in question was at the peak of her box office drawing power and attached to a home studio where Astaire was not under contract (he came out of retirement for the Garland film and was soon after put back on contract at MGM). Astaire took second billing to only one other performer during his heyday, and that was Bing Crosby in their two teamings at Paramount, Crosby's home studio.
As this film was conceived as a star vehicle for Betty Hutton, there are less Astaire numbers than one expects from one of his musicals, and only one solo: the celebrated "Piano Dance," in which he jaunts on, in, above and under a grand piano, culminating in a series of effortless suspensions over a succession of high-back chairs.
Fred Astaire was borrowed from Metro-Goldwyn-Mayer for this film, as Paramount had no star dancers under contract.
Composer-lyricist Frank Loesser was an old hand at writing specialty material for Betty Hutton, which required songs that could be performed at her signature breakneck speed. For this occasion, Loesser provided the especially manic "Can't Stop Talking About Him," which opens the film. In a send-up of Hutton's clarion belt, the song begins with an air raid siren that merges into a sustained note from Hutton.
Owing to the film's unusually heavy plotting, Let's Dance (1950), at 112 minutes, has one of the longest running times of Betty Hutton's star vehicles (only Incendiary Blonde  runs longer). Similarly, only three of Astaire's musicals run as long or longer: The Band Wagon (1953), Daddy Long Legs (1955) and Silk Stockings (1957).
One of only seven films Betty Hutton made in Technicolor. The others are Happy Go Lucky (1943), Incendiary Blonde (1945), The Perils of Pauline (1947), Annie Get Your Gun (1950), The Greatest Show on Earth (1952) and Somebody Loves Me (1952).
One of very few films that either Astaire or Hutton made that failed at the box office, largely attributed to an overplotted script and the uneasy blending of the stars' widely contrasting screen personas. Astaire had experienced the same phenomenon when he co-starred with Eleanor Powell in Broadway Melody of 1940 (1940), as Powell was accustomed to doing solo routines; however, their initial uneasiness was forgotten -- and forgiven -- when they joined forces for the incomparable "Begin the Beguine" duet, which remains one of the most revered dance sequences in Hollywood history. Alas, Let's Dance (1950) afforded no such opportunities for Astaire and Hutton to find common ground between their varied performance styles.
The film was hurried into production to take advantage of Fred Astaire's availability, part of the agreement MGM signed with Paramount to obtain Betty Hutton on loan-out for Annie Get Your Gun (1950) at Metro.
The western parody "Oh, Them Dudes" was inspired by Astaire's change-of-pace musical number "A Couple of Swells" in Easter Parade (1948), in which he and Judy Garland masqueraded as penniless and unshaven bums.
Frank Loesser wrote "Why Fight the Feeling?" as a love ballad, but there was no plot point to support its inclusion. In the end, the song was rendered by Betty Hutton in bizarrely comic fashion, going as far as to set her on fire, and climaxing with her high jump off a balcony and into a lake to douse the flames. Equally out of place is the ballroom dance reprise, in which Astaire fantasizes a romantic duet between himself and Hutton that is in no way linked to the plot.
A sharp illustration of how far Betty Hutton has fallen out of fashion since her heyday: Of her nineteen feature films, only five have been released in authorized digital editions. The primary interest in those films -- Star Spangled Rhythm (1942), The Miracle of Morgan's Creek (1943), Here Come the Waves (1944), Annie Get Your Gun (1950) and The Greatest Show on Earth (1952) -- extends well beyond Hutton's contributions, and none of them could be considered bona fide Hutton vehicles. Let's Dance (1950) was issued on VHS and laserdisc, but has yet to see the light of day on DVD or in high definition. Paramount's copyrights for The Stork Club (1945) and The Perils of Pauline (1947) expired in the 1970s and both titles remain in the public domain, issued in unauthorized, often butchered DVD and VHS editions. Staggeringly, the rest of Hutton's Paramount catalogue -- a whopping ten titles -- remains buried in the vaults: The Fleet's In (1942), Happy Go Lucky (1943), Let's Face It (1943), And the Angels Sing (1944), Incendiary Blonde (1945), Duffy's Tavern (1945), Cross My Heart (1946), Dream Girl (1948), Red, Hot and Blue (1949) and Somebody Loves Me (1952). Spring Reunion (1957), her last film, released through United Artists, can be seen only during its occasional airings on Turner Classic Movies.