Singing the "Sunnyside of the Street" is Darla Hood, best known as for her roles in the Our Gang comedies of the 1930s.
The Mocambo was a popular nightclub in Los Angeles in the '40s and '50s, catering to a host of celebrity patrons and showcasing the talents of many performers renown during that period. It was located at 8588 Sunset Blvd.