 Moro joined a childhood friend, Litto Nebbia, and three others in forming the pioneer Argentine rock and roll band Los Gatos, in 1966.The group became known for their all-night performances, and composed most of their own songs, many in the well-known neighborhood café, "La Perla del Once" (facing Plaza Miserere).One such composition, "La balsa" ("The Raft"), was written at that location by Nebbia and the ill-fated songwriter Tanguito on May 2, 1967, and following its release on the RCA Victor label on July 3, sold over 250,000 copies.