Flamenco sprang from a turbulent confluence of Spanish cultures that included Muslim Moors, Jews and Gypsies. It was the latter group that sustained it, passing on the music and dance through an oral tradition that placed a heavy emphasis on improvisation.

So Gypsy flamenco, presented by the Guitar Society of Fine Arts on Saturday with guitarist Gerardo Nunez, dancer Carmen Cortes, singers Rafael de Utrera and Jesus Mendez and percussionist Juan Manuel Lucas, may offer flamenco in its purest form.

Founding director Michael Chapman is calling it "raw and authentic." The Spanish call it "duende," that spontaneous event when the singers, musicians and dancers are caught up in a whirlwind of improvisation, a collective confluence of intensity and energy.

Spanish poet Federico Garcia Lorca said in a famous lecture that "duende is a force not a labour, a struggle not a thought. I heard an old maestro of the guitar say: 'The duende is not in the throat: the duende surges up, inside, from the soles of the feet.' Meaning, it's not a question of skill or technique, but of a style that's truly alive: meaning, it's in the veins: meaning, it's of the most ancient culture of immediate creation."

Chapman explains, "With the Gypsy style in each form, whether buleria, soleas or alegris, all the participating flamencos understand the basic rhythmic, melodic and harmonic structure and are able to do all sorts of variations playing off of and with each other -- a lot of the time not knowing what the others are going to do, but listening and looking and communicating with each other to create fresh moments all the time."

Although the Spanish often hold flamenco singers in high esteem and Americans are more familiar with dancers, the program will be led by Nunez, who is considered one of the top guitarists in the world, blessed with a virtuosic technique that seems to conquer "the impossible."

But even for an international artist such as Nunez, the ultimate "duende" can only come by sharing the emotional pool with his fellow artists.

"There is a spiritual dimension that gets into any performance," says Chapman. "But in flamenco, the whole purpose is to get to that point."