This is a great clip that Ramona reminded us of recently. From the movie "Straight to Heaven" (1939) here's "Millie and Bubbles" (dancing starts at 1:28).
Mildred Cruse was one of "Whyte's Hopping Maniacs"- Whitey's A-Team that included Frankie Manning and performed at the Cotton Club and toured Europe. She won the 2nd Harvest Moon Ball competition with dance partner Billy (or "Billie") Williams. While working she met a tap dancer named William Martin and after moving to Detroit and getting married they formed their own dance act of "Millie and Bubbles". You can read a great article/interview about her by Bob Crease from 1998 thanks to the Frankie Manning Foundation.