Chicho stepping Biagi. Rodolfo Biagi was the pianist in D'Arienzo's orchestra in 1935, he created the immensely influential "electric" stacatto rhythm. Biagi refined and purified his music style even sharper in his own orchestra, it's a very sharp stacatto that electrifies the dancers.
Tango Doble Frente / double front (tango al reves - inversed / reversed) in which the woman has her back to the man and the man embraces her around the waist, so both dancers face the front/public, it is a very historical style of tango (re)-invented by the popular milongueros such as Antonio Todaro. All steps that one dances in the regular, or "derecho" position, can be danced "al reves".
Milonga rhythm - This is Ney Melo Jennifer Bratt, filmed at La Nacional in NYC. See http://www.close-emb race.com/videolanaci onal.html for full video.