The music is arranged from an old Argentinian Folk song with a Waltz movement - in fact in the film- the mask of zorro- the two are not really doing a straight tango .. it is a mixture of both early tango dance steps and the argentinian Valz - which was a popular(of the people) dance step and not commonly played in well to do households. Tha Argentinian Valz has a number of similarities to the movements chosen for Tha Mask Of Zorro.. but I can definitely say that the song El Sombrero Blanco is decidedly nothing similar to the music played in the film... what a fuss.. it would have taken so little to listen to a version of it and the differnce would have been obvious to anyone..