Efraín (by now widely called "Moncito", or "Little Mon", and later called just "Mon") began to popularize his father's plenas. One of them, ""La Plena de Rafael Martinez Nadal"" was written in admiration for the Puerto Rican lawyer and legislator, who was extremely successful in local courts. Another one, ""Carbón de Palito"", described the route followed by street vendors of wood charcoal (then used as cooking fuel) through most of Mayagüez. Almost all sections of the city at the time are mentioned in the lyrics. Both plenas were local hits, and along with Rafael Cortijo's rendition of "El Bombón de Elena", they helped to revive the genre during the late 1950s. Efraín started writing his own material just as this happened.