Duende
Poet Frederico Lorca wrote an essay about Duende, which has affected everything I have ever done since. It is the highest point of artistic expression, brought to the edge of a knife by deep passion from within.
. . . The duende, then, is a power and not a construct, is a struggle and not a concept. I have heard an old guitarist, a true virtuoso, remark, “The duende is not in the throat, the duende comes up from inside, up from the very soles of the feet.” That is to say, it is not a question of aptitude, but of a true and viable style—of blood, in other words; of what is oldest in culture: of creation made act. . . .
See the full essay here: http://www.angelfire.com/wa2/margin/LorcaDuende.html