When Grim Natwick first drew the character that became Betty Boop for Fleischer Studios, a song made popular by Helen Kane was the direct inspiration. Kane had made a career with her high voice, big eyes, and the "boop-boop-a-doop" she would insert into songs. Kane was so upset that Fleischer stole her act for the cartoon character that she sued. But karma intervened, as it turned out that Kane did not originate the "boop-boop-a-doop" act, but appropriated it from a Cotton Club headliner named Esther Jones, also known as Baby Esther.
Tipped to be the next Josephine Baker, her real name was Gertrude Saunders and African American historians believe that she “coined” the famous words “Boop-Boop-a-Doop”, first uttering them on stage at the Cotton Club. Jazz studies scholar Robert O’Meally, referenced by the Harlem World Magazine, even referred to Saunders as Betty Boop’s “black grandmother.” But somewhere between 1927 and 1928, a white Broadway actress and singer, Helen Kane, caught one of Esther’s performances and almost immediately began using the “boops” in her songs.
An article at Messy Nessy Chic tells the story of Esther Jones, Helen Kane, and Betty Boop, but only after running down the fascinating history of the Cotton Club itself.