The trio was formed in the context of the radio show Música em Surdina, presented by singer Paulo Tapajós at Rádio Nacional.

[1] The trio's name alludes to the radio show in which it debuted and to its musical style, featuring suave, muted melodies in contrast to the louder styles preferred by the orchestras and crooners of the late 1940s and early 1950s.

[2] The trio's first formation recorded four albums, all published by Musidisc, a label owned by the singer and producer Nilo Sérgio.

[3] Bassist Pedro Vidal Ramos and percussionist Bicalho also contributed to some of the tracks.

The nod to "restraint" is not a part of the trio's name only: their performances show a particular interrelationship between instruments in what concerns the rhythmic-harmonic conduction, interpretation of the main melody, secondary themes, etc., in which its style is kept free of "excesses" or "artificial" elements.