Hi List members: I was listening yesterday a Cd By Reinhard Goebel and
Musika Antiqua Koln that included a marvelous sonata by Vivaldi which
is based on "La Folia".  Some other composers have composed Variations
on this "Leave", so my question is: What exactly is "La Folia de Espana"?
What other composers have used?  Any comments?

Thanks in advance
Arturo Llamas