On St. John’s Day in the city of Valls in the Catalan region of Spain, a touring acrobatic company, or comparsa, presents the human tower of Valls. The acrobats form human towers or pyramids with four to six men at the base and one or more children at the top. The towers can extend to eight times a man’s height, and they are formed to the musical accompaniment of the gralla, or native oboe. There is a point during the performance at which the children on top salute, the music ceases, and the entire structure stands immobile for several seconds before collapsing gracefully to the ground. Discuss