“Two Girls on Broadway” is a 1940 musical film directed by S. Sylvan Simon, and starring Lana Turner and Joan Blondell.
The film is a remake of “The Broadway Melody” (1929).
Molly Mahoney (Joan Blondell) forms a vaudeville act with her fiancé Eddie Kerns (George Murphy).
Working at a local dance school, she longs to become a star performing on Broadway.
Eddie persuades her to leave town for New York City, and after their arrival, Eddie debuts on the radio with his so-called singing canaries.
Although the canaries are unable to sing, Eddie is not, and following an impressive debut he is offered a job at the station.
He convinces co-worker Buddy Bartell (Richard Lanez) to grant Molly and her little sister Pat (Lana Turner) an audition.
What promised to be a big opportunity turns into the start of noticeable tensions between the sisters, when Bartell announces he wants to team Eddie and Pat. Molly, meanwhile, is offered a degrading job selling cigarettes. Instead of complaining, Molly swallows her pride and allows Pat to take the limelight meant for her. Meanwhile, wealthy and often-married playboy ‘Chat’ Chatsworth (Kent Taylor) falls for Pat and starts flirting with her. After a while, Molly finds out about Chat’s wild past through her gossipy friend Jed Marlowe (Wallace Ford), and tries to warn her sister.
Her worries turn out to be unnecessary, though, as Pat feels more attracted to Eddie.
She does not want to hurt Molly’s feeling or ruin her engagement, and decides to return home.
Molly, who is unaware of Pat’s motives for leaving, insists that she stay.
Thinking it is the only way of forgetting her feelings for Eddie, Pat accepts a proposal from Chat and elopes with him.
When Eddie hears about this, he is alarmed, because he had been secretly in love with Pat the entire time.
He admits his true feeling for Pat to Molly, and is encouraged to follow her. However, upon arriving at the apartment, Eddie finds out that Pat and Chat have already left.
Overhearing one of Chat’s servants of Pat and Chat’s whereabouts, Eddie rushes to City Hall.
Breaking up a wedding ceremony that has already begun, Eddie professes his love for Pat.
With the blessing of Molly, Pat and Eddie decide to marry, while Molly returns home.

Lana Turner plays Patricia ‘Pat’ Mahoney.

After a headlined marriage (with Artie Shaw) and cover stories in both Life and Look just weeks apart, the America of 1940 was so Lana Turner-conscious, that MGM’s ad campaign for her next film shouted: “The Girl They’re All Talking About! She Puts It Back On the Screen.” 
The grace and precision of the Turner-Murphy team is worth the entire weigth of the film, especially in the dazzling “My Wonderful One” production  number which utilized a spectacular revolving stage and a large number of dance extras.

Dance:

You can watch the film here

Lana Turner did a lot of movies. She really loved being a moviestar.
Here are the most important films in which she starred. Just click the links for more info, photos and videos.

20 April 1937: A Star Is Born
9 Oct. 1937: They Won’t Forget
24 Oct. 1937: The Great Garrick
1 Jan. 1938: The Adventures of Marco Polo
22 July 1938: Love Finds Andy Hardy
12 Aug. 1938: Rich Man, Poor Girl
9 Dec. 1938: Dramatic School
28 April 1939: Calling Dr. Kildare
18 Aug. 1939: These Glamour Girls
29 Sept. 1939: Dancing Co-Ed
19 April 1940: Two Girls on Broadway
19 July 1940: We Who Are Young
25 April 1941: Ziegfeld Girl
12 Aug. 1941: Dr. Jekyll and Mr. Hyde
2 Oct. 1941: Honky Tonk
18 Febr. 1942: Johnny Eager
27 Aug. 1942: Somewhere I’ll Find You
1 April 1943: Slightly Dangerous
19 Aug. 1943: Du Barry Was A Lady
13 Nov. 1943: The Youngest Profession
23 Aug. 1944: Marriage Is a Private Affair
8 March 1945: Keep Your Powder Dry
1 Oct. 1945: Week-End At The Waldorf
2 May 1946: The Postman Always Rings Twice
5 Nov. 1947 : Green Dolphin Street
1 Nov. 1947: Cass Timberlane
29 April 1948: Homecoming
20 Oct. 1948: The Three Musketeers
1 Sept. 1950: A Life Of Her Own
2 March 1951: Mr. Imperium
5 Sept. 1952: The Merry Widow
25 Dec. 1952: The Bad And The Beautiful
25 Aug. 1953: Latin Lovers
1 May 1954: Flame And The Flesh
7 Sept. 1954: Betrayed
13 May 1955: The Prodigal
4 June 1955: Sea Chase
14 Dec. 1955: The Rains Of Ranchipur
12 Jan. 1956: Diane
13 Dec. 1957: Peyton Place
30 Jan. 1958: The Lady Takes A Flyer
2 May 1958: Another Time, Another Place
30 April 1959: Imitation Of Life
23 June 1960: Portrait In Black
19 July 1961: By Love Possessed
2 Nov. 1961: Bachelor In Paradise
25 Dec. 1962: Who’s Got The Action?
24 Febr. 1965: Love Has Many Faces
27 April 1966: Madame X
30 April 1969: The Big Cube
7 Nov. 1974: Persecution
27 Oct. 1976: Bittersweet Love
31 Oct. 1980: Witches Brew
21 May 1982: Dead Men Don’t Wear Plaid

Sources: Wikipedia, IMDB, Rotten Tomatoes, Lana’s biography “Lana, the Lady, The Legend, The Truth“, “The Films Of Lana Turner” by Lou Valentino and “Lana Turner, The Memories, The Myths and The Movies” by Cheryl Crane.