Jones used scat, a singing technique used in jazz composed of dynamic and nonsensical syllables instead of words, which can, at times, sound similar by comparison to create the " Boop-oop-a-doo " performance. This signature "Boop-oop-a-doo" expression landed Betty Boop in a court trial in the 1930s-- the plaintiff being Helen Kane."Boop-oop-a-doop! (Oop!)" Sweet Betty!" — A shortened version of Betty's theme song. Pioneering cartoon series (from 1930-1939, plus a few one-off revivals) from Fleischer Studios