Kane attempted to sue the studio for claims of stealing her signature "boop-oop-a-doop" style, but the judge decided that the proof of this was insufficient, thus dismissing the case.

[5] She spent the early 1920s trouping in vaudeville as a singer and kickline dancer with a theater engagement called the "All Jazz Revue".

Subsequently, Paul Ash, a band conductor, put Kane's name forward for a performance at New York's Paramount Theater.

[citation needed] Kane's first performance at the Paramount Theater in Times Square proved to be her career's launching point.

In the opening credits of Pointed Heels, Kane and William Powell are billed on the same line just below the title, with Fay Wray and the rest in smaller letters underneath.

In 1930, Fleischer Studios animators introduced what was alleged to be a caricature of Helen Kane,[8] with droopy dog ears and a squeaky singing voice, in the Talkartoons cartoon Dizzy Dishes.

In May 1932, Kane filed a lawsuit against Max Fleischer and Paramount for damages of $250,000 (equal to $5,582,927 today), alleging infringement, unfair competition and exploitation of her personality and image.

[9][10] Before his death, cartoonist Grim Natwick admitted he had designed a young girl based upon a photo of Kane.

Margie Hines, Mae Questel, Bonnie Poe, Little Ann Little, and Kate Wright provided the voice for Betty Boop.

It was claimed in court that Kane based her style in part on Baby Esther, a child African American dancer and entertainer of the late 1920s, known for impersonating Florence Mills.

[17] The Fleischers used as defense a film of Baby Esther, made in 1928, featuring her singing three songs that had earlier been popularized by Helen Kane – "Don't Be Like That", "Is There Anything Wrong with That?""

and "Wa-da-da" – which writer Mark Langer says "was hardly proof that Helen Kane derived her singing style from Baby Esther".

[18] However Jazz Studies scholar Robert O'Meally stated this evidence might very well have been fabricated by the Fleischers to discredit Kane, whom they later admitted to have been their model for Betty Boop.

[20][21] With the hardships of the Great Depression biting, the flamboyant world of the flapper was over, and Kane's style began to date rapidly.

In 1950, she dubbed Debbie Reynolds, who performed "I Wanna Be Loved by You" in the MGM musical biopic of songwriters Bert Kalmar and Harry Ruby, Three Little Words.

[25] The release dates of recordings 1 to 22 are derived from the cover notes of the CD Helen Kane - Great Original Performances - 1928 to 1930 (RPCD 323).