Alemán was orphaned at age of ten when his mother died and his father committed suicide. He sustained himself by working sporadically as a dancer and musician on the streets of Santos, Brazil. When he saved enough money, he bought a guitar and started to play professionally at party venues in a duo called Los Lobos (Les Loups) with his friend, Brazilian guitarist Gastón Bueno Lobo. The duo moved to Buenos Aires in 1925 to work under contract for the comedian Pablo Palitos. In Buenos Aires, they formed a trio with violinist Elvino Vardaro. They added tango to their repertoire and recorded with Agustín Magaldi. They later played with Carlos Gardel and Enrique Santos Discépolo.