On their first album, O Terço (1970) was not yet full on prog, but it is a seminal work in the history Brazilian progressive music.

Terço II (1973) would see them moving from Psychedelic to heavier sounds, along the lines of King Crimson and Led Zeppelin.

[1] It was a big hit, gave Brazil its first classic prog album, and solidified O Terço's place in music history.

A possible reformation of the classic Criaturas da Noite (1975) lineup was in the works in 2001/2002, but an unexpected death of their drummer postponed the idea to 2005, when they made a couple of live presentations, only in Brazil.

O Terço's musicians were widely successful in other Brazilian groups, chiefly 14 Bis, which had a softer and less progressive sound.