Some of the information is Boop-Oop-a-Dooping full of SPOILERS. Boop-Oop-a-Doop!
"Boop-De-Dooden-Do" is the one true predecessor of Helen Kane's Boop-Boop-a-Doop. "Boop-De-Dooden-Do" was originated by African-Americans of the 1850s and was interpolated in unction while they sang old-time hymns. According to to white Americans in 1852, their singing had no counterpart or competition in the white race and that it wouldn't be the music of the future. Although, several decades later, things of course changed and then everybody wanted to emulate African-Americans' scat singing style that they had originated, which was later adapted by numerous others.