One of the most important historic old-guard sambistas, Mano Décio da Viola wrote more than 500 sambas and participated in several samba schools since their inceptions. Together with his partner Silas de Oliveira, Mano Décio was one of the pioneering writers of samba-enredos. Other of his successes were Lá Vem Ela Com Uma Trouxa de Roupa na Cabeça (recorded by Raul Marques in 1942), Apoteose ao Samba (recorded by Jamelão in 1950), and Olelê, Olalá (recorded by Adilson Ribeiro in 1973). Mano Décio recorded the first of only three albums as an interpreter at 66.

The first rancho in which he participated was the Príncipe das Matas (organized by his family in the Mangueira hill), when he was 14. He also participated in the bloco Vai Como Pode (that would become the Portela samba school) and in the Recreio de Ramos samba school. In that period (1930), he wrote his first samba, Vem, Meu Amor (with Bide/João de Barro), recorded by Almirante five years later. It represented a typical malandragem (street smartness), as the melody was copied from that of Emil Waldteufel's valse The Skaters. Mano Décio was appointed samba director of the Prazer da Serrinha samba school, where he became known as Mano Décio da Viola. The first samba-enredo ever (Conferência de São Francisco) was written by him and Silas de Oliveira, in 1946 (before that, all samba school sambas were sambas-de-terreiro). In 1949, he left the Prazer da Serrinha and joined the Império Serrano samba school (formed two years before due to a dissension in the Prazer da Serrinha), which won the annual Carnaval contest four times with Mano Décio's sambas-enredo (the samba school paraded 19 years to his creations). In that same year, the Império Serrano won the contest with the samba-enredo that became one of the most important classics of the genre, Tiradentes (Mano Décio/Penteado/Estanislau Silva). In 1951, the samba school won with Batalha Naval do Riachuelo (Mano Décio/Penteado/Molequinho); in 1955, with Exaltação a Duque de Caxias (Mano Décio/Silas de Oliveira); and in 1960 with Medalhas e Brasões (Mano Décio/Silas de Oliveira). ~ Alvaro Neder, Rovi