Some dance forms are all about the air, about overcoming gravity in order to fly, but flamenco is about the earth, a kind of mournful connection to place that is only possible for a nomadic people. The dancers attack the ground with their powerful footwork, the singers seem to dredge their voices up from the rocks. Even in their most lighthearted moments, their straight spines and proud carriage anchor these artists to the dirt under their feet, whether at the campfires they originally danced around, the floors of the taverns they gathered in, or the stages they perform on today. Noche Flamenca, founded in 1993 in Madrid by Martin Santangelo and Soledad Barrio, has carried this authentic relationship to the earth on multiple world tours; returning to Seattle, their performances will reflect the passion and anguish that have made them famous. SANDRA KURTZ