what is a piano baby?

I was wondering if anyone could tell me what a piano baby is exactly? It seems that they are child like figurine. Other than that, were they made in a certain era? How do you tell the difference between them and other figurines of children? Any help would be appreciated. Thanks!

Piano Baby: What a beauty! She has so much detail with her basket and grapes. She is open domed … She looks like an unmarked Heubach piano baby.

Les chevaliers de la table ronde: lego animation