He collaborated with artists such as Francisco Alves, Carmen Miranda, Aracy de Almeida and Noel Rosa and was particularly successful as a radio singer.

[2] He recorded many hits with Carmen Miranda and Francisco Alves, with whom also performed frequently in the 1930s, all of which are regarded as amongst the finest Brazilian singers of this period.

As a singer, he was known for his gentle tone, which compensated for the lack of vocal power.

His singing style even today sounds modern and he is considered one of the pioneers of bossa nova.

In 1995, Julio Bressane made a film called The Mandarin about the Brazilian popular music of the 20th century, focusing especially on the life and work of Mário Reis.