A most active session musician from the dawn of the recording industry in Brazil, Louro started to take music classes in the band kept by the clothing factory Companhia Manufatora Fluminense, where he worked. At 16, he left the band and was hired to conduct the 70-member band Euterpe Rio-Bonitense. His adaptation of a popular theme, called by him the "Dança do Urubu," became famous after its recording by Pixinguinha and his Oito Batutas in 1922 as "Urubu Malandro"; a favorite theme of the choro repertory due to its structure and harmony, extremely suited for improvisations, still popular today. Playing in every venue of Rio de Janeiro and Niterói, Louro became known around and, helped by Chiquinha Gonzaga, he formed the Grupo do Louro (clarinet, cavaquinho, and guitar); which realized many recordings for the Casa Edison, including the original "Moleque Vagabundo," which had success. Louro also realized the first recording of "Urubu Malandro" in 1914, and in 1919 he performed with his group in the João Caetano theater during the presentation of the revues A Juriti (Viriato/Chiquinha Gonzaga) and As Pastorinhas (Abadie Faria Rosa/Paulino Sacramento). Two years later, he went to Europe where he performed, accompanied by a new group, at the Olímpia theater in Lisbon, Portugal. Returning to Brazil, Louro continued to record and play the saxophone and the clarinet in several different orchestras.