La Folia d’ Espagna is a well-known baroque theme. Composers like Georg Friedrich Haendel and Antonio Salieri (the guy who nowadays owns his reputation from the movie Amadeus by Milos Forman) used the theme as the basis for a Theme and Variations. Even Mauro Giuliani used it in the classical era.
Gaspar Sanz published his version in the Instruccion de Musica. I made a clean score of it, without ornaments and thrills. These are up to you, as was customary in the baroque era, within specific rules of course.