Baby Rose Marie Mazetta sings (Baby Boys) Don't Be Like That, and even sings a little scat. The film is from a segment of a June 1929 Warner Brothers Vitagraph soundie "The Child Wonder", reel #809.
Rose Marie was born August 1923 so she would have been two months shy of her sixth birthday when this was produced. Rose Marie was born in New York City, daughter of an Italian American father and a Polish mother, Stella Gluszak.