Many a Victorian middle-class home's parlor had a piano with a bisque or porcelain doll on top. The piano was covered with some type of shawl or covering with the doll in various positions; crawling, sitting, on its tummy, or on its back playing with its toes. They could be clothed in a molded nightgown or nude and range in size from 3" to 18". Size is important in determining value. The larger the piano baby, the greater the value.
The most well-known manufacturer of the piano babies was a German company "Heubach Brothers of Germany". The company has been in existence since the 1800's in Lichte, Thuringia, Germany and specializes in novelty figurines and doll heads. As of 2005, it is known as Lichte Porcelain. Their "piano babies" were almost always marked by the company's sunburst design.
Watch out for reproductions! There are some that are reputable makers of piano babies that advertise them as reproductions. However, there are others that advertise them as being originals or say nothing at all, leaving the buyer believing they are originals.