* Blood Wedding is an unexpected treat for admirers of Spanish dance, Spanish drama, and Spanish culture in general. Directed by Carlos Saura, Spain's leading filmmaker at the moment, it takes the classic play by Federico Garcia Lorca - about tensions that lead to tragedy when a controversial marriage takes place in a Spanish town - and translates it into the terms of flamenco dance. Saura takes a rigorous approach, presenting the dance as a filmed dress rehearsal on a bare stage (rather than a finished production) and thereby restricting the spectacle of the experience. Also, he finds few visual equivalents - choreographic or cinematic - for the luxurious verbal qualities of Garcia Lorca's elegant poetry and prose. Yet the screen version of ''Blood Wedding'' is an exotic and stimulating event, moving to heights of real excitement in its darkly graceful slow-motion climax. Though his career has been uneven, Saura is clearly one of the most adventurous of current European filmmakers.