As he has done before with other dance forms alien to his background (flamenco, kathak or Shaolin rites, for instance), the prolific choreographer Sidi Larbi Cherkaoui has plunged into Tango with an avid curiosity and sensitive perception. His new work M¡longa, a Sadler’s Wells production that premièred in Mézières, Switzerland, earlier this year, reflects his learning journey.