It has been claimed, and it has been proven, that the Duncan Sisters are perpetual pep. Ever since their songs as children were the delight of Los Angeles, they have evinced this wild endeavor, and it hasn't stopped. Rosetta and Vivian are always up and doing. It was while playing in vaudeville that Rosetta's long desire to play a darky role was developed, and it stayed in that fertile little brain of hers until after their present musical comedy success "Topsy and Eva" was evolved. Catherine Chisholm Cushing wrote the book and the Duncans composed the score and lyrics.

  Rosetta just loved to black up, while sister Vivian has just the ideal pink-and-white appearance of the saccharine and tearful Eva.

"Grows Into Idea."

  Blacking up for more than two years has had a psychological effect on Rosetta, and it has grown into a regular idea. Just as she originated the idea of novel situations and different melodies for their current success, she now comes forward ably assisted by angel-faced Vivian, and says that it is time to do something for the perpetuity of the pickaninny. The kinky-haired little imp that "just growed" ought to be immortalized not singly, but in ensemble.

  So right now between scenes, and in spare moments off the stage, they are working on the score and story of a ballet—a blackface ballet. It is to be all pickaninny and starts 'way back in the folklore days, comes along thru plantation times up to the first ragtime, grazes around the edge of syncopation and ends up with modern and joyful jazz. The Duncan girls' idea is to tell the whole story of negro melody from the beginning to the end.

  The Duncan sisters in their musical comedy classic will come to the Broadway theater for the week beginning Monday, April 12.