Twelve days of the Infanta Margarita is a fiction but it is so well supported that it is hard to believe that it is not true. The evidence both amazes and delights, much of it is fact, some is legend, some fairy story, some children's games, but the most important are two portraits, "Las Meninas' and "The Rokeby Venus" by the Spanish painter Diego de Velasquez . The story begins in the princess's 15th year when she refuses to be a subject for another portrait in formal court dress and, to make a point, she insists she will be painted in the nude. The story then proceeds through the sequence of gifts that we know in the Carol "The Twelve days of Christmas" starting with the partridge and ending with the twelve lords a-leaping. The work is a performance-piece for a small vocal group. A narrator provides the continuing thread of the story which is supported by a number of musical arrangements most of which are based upon familiar Irish and Scottish airs. As few as three can perform the work and as many as twelve. It has been successfully presented in different venues from coffee shop to concert hall. The performance time is about ninety minutes.