Ruby Keeler, born Ethel Hilda Keeler, (August 25, 1910 – February 28, 1993) was an actress, dancer and singer most famous for her on-screen coupling with Dick Powell in a string of successful early musicals at Warner Brothers, particularly 42nd Street (1933). From 1928 to 1940, she was married to singer Al Jolson. She retired from show business in the 1940s but made a widely-publicized comeback on Broadway in 1971.

Keeler was born in Dartmouth, Nova Scotia, Canada, to an Irish Catholic family, one of six siblings. Two sisters, Helen and Gertrude, had brief performing careers. Her father was a truck driver, and when she was three years old, her family packed up and moved to New York City where he knew he could get better pay. But it was not enough: there were six children, and although Keeler was interested in taking dance lessons, the family could not afford to send her.

Richard Ewing "Dick" Powell (November 14, 1904 – January 2, 1963) was an American singer, actor, producer, director and studio boss. Though he came to stardom as a musical comedy performer, he successfully transformed into a hardbitten leading man of darker projects.

Born in Mountain View, the seat of Stone County in northern Arkansas, Powell attended the former Little Rock College in the state capital, before he started his entertainment career as a singer with the Charlie Davis Orchestra, based in the midwest. He recorded a number of records with Davis and on his own, for the Vocalion label in the late 1920s.

Powell moved to Pittsburgh, where he found great local success as the Master of Ceremonies at the Enright Theater and the Stanley Theater. In April 1930, Warner Bros. bought Brunswick Records, which at that time owned Vocalion. Warner Bros. was sufficiently impressed by Powell's singing and stage presence to offer him a film contract in 1932. He made his film debut as a singing bandleader in Blessed Event. He went on to star as a boyish crooner in movie musicals such as 42nd Street, Footlight Parade, Gold Diggers of 1933, Dames, Flirtation Walk, and On the Avenue, often appearing opposite Ruby Keeler and Joan Blondell.

Busby Berkeley (November 29, 1895 – March 14, 1976) was a highly influential Hollywood movie director and musical choreographer. Berkeley was famous for his elaborate musical production numbers that often involved complex geometric patterns. Berkeley's works used large numbers of showgirls and props as fantasy elements in kaleidoscopic on-screen performances.

Berkeley was born to stage actress Gertrude Berkeley. Among Gertrude's friends were actress Amy Busby and actor William Gillette, then only four years away from playing Sherlock Holmes. Gertrude apparently named her son after both Busby and Gillette after they agreed to be the boy's godparents. The boy was named Busby Berkeley William Enos.

In addition to her stage work, Gertrude played mother roles in silent films while Berkley was still a child. Berkeley made his stage debut at five, acting in the company of his performing family. During World War I, Berkeley served as a field artillery lieutenant. Watching soldiers drill may have inspired his later complex choreography. During the 1920s, Berkeley was a dance director for nearly two dozen Broadway musicals, including such hits as A Connecticut Yankee. As a choreographer, Berkeley was less concerned with the terpsichorean skill of his chorus girls as he was with their ability to form themselves into attractive geometric patterns. His musical numbers were among the largest and best-regimented on Broadway.^{[citation needed]}

Lloyd Francis Bacon (December 4, 1889 – November 15, 1955) was a screen, stage, and vaudeville actor and film director.

Bacon was born in San Jose California, the son of actor Frank Bacon, later the co-author and star of the long running Broadway show 'Lightnin' (1918), and Jennie (Weidman) Bacon. He was not related to actor Irving Bacon whom he directed in a number of his films. Bacon attended Santa Clara University, and would later include highlights from the Bronco Football program in the end of his famous film, Knute Rockne, All American.

Bacon started in films with Charlie Chaplin and Bronco Billy Anderson and appeared in more than 40 total. As an actor he is best known for supporting Chaplin in such films as 1915's The Tramp, The Champion and 1917's Easy Street.

He also directed over a hundred films between 1920 and 1955. He is best known as director of such classics as 1933's 42nd Street, 1937's Ever Since Eve from a screenplay by the playwright Lawrence Riley et al., 1938's A Slight Case of Murder with Edward G. Robinson, 1939's Invisible Stripes with George Raft and Humphrey Bogart, 1939's The Oklahoma Kid with James Cagney and Humphrey Bogart, 1940's Knute Rockne, All American with Pat O'Brien and Ronald Reagan (as "the Gipper"), 1943's Action in the North Atlantic, and 1944's The Fighting Sullivans with Anne Baxter and Thomas Mitchell. He also directed Wake Up and Dream (1946).

Al Jolson (May 26, 1886 – October 23, 1950) was an American singer, comedian, and actor. In his heyday, he was dubbed "The World's Greatest Entertainer".

His performing style was brash and extroverted, and he popularized a large number of songs that benefited from his "shamelessly sentimental, melodramatic approach". Numerous well-known singers were influenced by his music, including Bing CrosbyJudy Garland, rock and country entertainer Jerry Lee Lewis, and Bob Dylan, who once referred to him as "somebody whose life I can feel". Broadway critic Gilbert Seldes compared him to "the Greek God Pan", claiming that Jolson represented "the concentration of our national health and gaiety."

In the 1930s, he was America's most famous and highest paid entertainer. Between 1911 and 1928, Jolson had nine sell-out Winter Garden shows in a row, more than 80 hit records, and 16 national and international tours. Although he's best remembered today as the star in the first (full length) talking movie, The Jazz Singer in 1927, he later starred in a series of successful musical films throughout the 1930s. After a period of inactivity, his stardom returned with the 1946 Oscar-winning biographical film, The Jolson Story. Larry Parks played Jolson with the songs dubbed in with Jolson’s real voice. A sequel, Jolson Sings Again, was released in 1949, and was nominated for three Oscars. After the attack on Pearl Harbor, Jolson became the first star to entertain troops overseas during World War II, and again in 1950 became the first star to perform for G.I.s in Korea, doing 42 shows in 16 days. He died just weeks after returning to the U.S., partly due to the physical exertion of performing. Defense Secretary George Marshall afterward awarded the Medal of Merit to Jolson's family.