“Mano a mano” is one of the most popular pieces of the tango canción repertoire. It was written by Celedonio Flores with the music of Carlos Gardel and Jose Razzano in 1923. Like “Yira Yira” it’s popularity goes beyong the genre of tango with recent pop and rock recordings.
Like many other tangos of the early 1920’s, “Mano a mano” is a sentimental song about a man who lost a woman. It is based on the personal story of a young singer named Nunciatta. Nuciatta told Celedonio Flores about his love affair before he died of tuberculosis. Celedonio Flores turned Nuciatta’s story into a poem which was recorded as a tango in the style of Mi noche triste by Carlos Gardel in 1923.
Gardel was not fully dedicated to tango at the time he recorded “Mano a mano”. However the song became one of the highlights of his repertoire and the 1923 acoustic recording was followed by another one in 1928 with microphone and electrical technologies. “Mano a mano” was also featured in a series of short films by Carlos Gardel in 1930, turning it one of the very first video clips ever produced. 
Other artists who recorded “Mano a mano” in the 1930’s include Charlo (1934), Francisco Canaro with Roberto Maida (1938) and Hugo del Carril (1939).
When “Mano a mano” was banned by the military government in 1943, Celedonio Flores wrote an alternative version whitout the controversial lunfardo expressions. “Rechiflado en mi tristeza” was replaced by “Te recuerdo en mi tristeza” and so on.  This new version entitled “Con gomina” was recorded by Francisco Lomuto with Alberto Rivera in 1944 but never had much success.
After the prohibition was lifted in 1949, “Mano a mano” found it’s way back to the repertoire of various prominent signers including Ranko Fujisawa (1955), Edmundo Rivero (1962), Julio Sosa (1961) and Roberto Goyeneche (1978). Recent recordings include pop, rock and ranchera versions by Julio Iglesias (1996), Andres Calamaro (2006) and Vicente Fernandez (2014).
Two other alternative versions of “Mano a mano” have been published to this day. One by Humberto Correa where the woman exposes her point of view and another by Chilean Pepe Aguirre depicting the protagonist as a man who neglected his woman and got the treatment he deserved. 
 Del Priore, Oscar, and Irene Amachástegui. Cien tangos fundamentales. Buenos Aires: Aguilar, 1998.
 Taboada, Pablo. La otra letra de Mano a mano. Investigación tango, 2013. Online http://www.investigaciontango.com/inicio/index.php?option=com_content&view=article&id=181:mano-a-mano-y-la-censura-lunfarda&catid=41:lunfardo&Itemid=61
 Rasore, Alberto. Gardel en los cortometrajes de 1930. Buenos Aires Antiguo, 2006. Online. http://www.buenosairesantiguo.com.ar/carlosgardel22.html