It is from the 1944 film, Broadway Rhythm, and it features the three Ross Sisters in a rendition of Solid Potato Salad. I'm not exactly sure what "solid potato salad" means, but the song is spectacular nonetheless.
The Ross Sisters were a trio of singers and dancers comprising the sisters Betsy Ann Ross, Veda Victoria (Vicky) Ross, and Dixie Jewel Ross, who used the stage names Aggie Ross, Maggie Ross, and Elmira Ross respectively. They performed as a three-part harmony trio, who also danced and have become particularly noted for their acrobatics and contortionism. Their careers peaked during the 1940s, when they featured prominently in the 1944 film Broadway Rhythm. Footage appeared in the compilation film That's Entertainment! III (1994)
Betsy Ann Ross, Dixie Jewel Ross, and Veda Victoria Ross, known as Aggie, Elmira, and Maggie respectively, were three Texas born sisters who had moderate success in showbiz in the 1940′s.
They were known for snazzy dances that incorporated incredible contorted moves.
The sisters were born in West Texas, the daughters of Charles Adolphus and Veda Cordelia Ross. Shortly after appearing in the 1944 film Broadway Rhythm, they moved to Europe where they appeared in Piccadilly Hayride, a London stage revue that ran from 1946 to 1948. They also recorded "Five Minutes More," a song later covered by Frank Sinatra.
Sources differ over the marriages and deaths of the sisters.
Betsy Ann (Aggie) was born on June 26, 1926, in Colorado City, Texas. She married Robert "Bunny" Hightower, an American dancer, on January 11, 1947. It has been claimed that he was an alcoholic suffering schizophrenia who on one occasion beat Betsy so badly that she almost died. They appeared together many times on The Ed Sullivan Show and had a son. Hightower was previously married to dancer Vera-Ellen, best known as Rosemary Clooney's sister in the film White Christmas. While being a performer most of her career, in 1976 she worked as a production assistant in a Broadway dance production.
Veda Victoria (Maggie) was born on November 8, 1927, in Roscoe, Texas. According to official sources, she married English entertainer Dickie Henderson (1922--1985) in London on July 10, 1948. Henderson and his wife had a son Matthew, in 1951 and a daughter Linda, in 1954. According to official records, Vickie died aged 35 on 10 July 1963.
Dixie Jewel (Elmira) was born on August 9, 1929, in Loraine, Texas.
Some unofficial sources, including genealogy websites, refer to Henderson's wife as Dixie; give her date of death as 10 July 1963; and state that she is buried in Gunnersbury Cemetery, Acton, Greater London. Unofficial sources also refer to Vicky - rather than marrying Dickie Henderson - as having married, first, ventriloquist Robert Lamouret in Paris in 1950, and then Bob Hender in 1959
The dance starts of innocuous enough until you get to about the one minute mark. That's when the mind-blowing body contortions begin!