Toño Rosario and his brothers were always interested in music. From young, they recall finding whatever instruments they could in household items since they were born in poverty and could not afford real musical instruments. The group in which Toño started his musical career was formed in 1978 and its name is "Los Hermanos Rosario": it consisted of himself, his brothers Pepe and Rafa (as the lead singers) and brothers Luis, Tony, and Francis (as the instrument players). They used to play in their neighbors houses and this is how they eventually got to be known and discovered. After the death of their brother Pepe, Toño and Rafa took the lead in the band with Toño as the main singer due to his unique and highly recognized voice.