Onstage, professional couples from 32 countries around the world are competing in the two categories of the championship: tango salon and tango stage. Backstage, participants wait and prepare before the competition. Photos by Natacha Pisarenko / Associated Press

Couples from around the world competed in the finals of Argentina's annual tango competition in late August. The highlight of the event is a ceremony to honor Astor Pantaleon Piazzolla, the legendary composer and bandoneon player, who revived the genre and infuriated purists by blending tango with rock music in the 1970s.