In the late 1950s, Soares spent one year touring Argentina with Mercedes Batista. She became popular with her first single "Se Acaso Você Chegasse", on which she introduced scat singing "à la" Louis Armstrong, adding a bit of jazz to samba, however, Elza says that she did not know American music at the time. She moved to São Paulo, where she performed at theaters and night clubs. Her husky voice became her trademark. After finishing her second album, "A Bossa Negra", she went to Chile to represent Brazil in the 1962 FIFA World Cup and met Louis Armstrong.