O Terço was one of the first progressive rock bands from Brazil. The band, whose name means "rosary beads" in Portuguese, first formed in 1968.
Personnel changes would become part of the bands dynamic, with Sergio Hinds assuming the role of band anchor. The group owed a lot of its early sound to such Italian favorites as Locanda Delle Fate, Quella Veccia Locanda, and Premiata Forneria Marconi. They also managed to mix in other styles, like folk, and the most important: MPB (Brazilian Popular Music), which made the band sound a little bit like Milton Nascimento, Tom Jobim and other great Brazilian artists.
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. There are obvious influences of the Moody Blues, and Pink Floyd. Terço II (1973) would see them moving from Psychedelic to heavier sounds, along the lines of King Crimson and Led Zeppelin. It was 1975's Criaturas da Noite that became a monumental success. It was a big hit, gave Brazil its first classic prog album, and solidified O Terço's place in music history.
In the 1980s, the band began to tour the United States and Europe. This would make them more popular in other parts of the world, than they were at home.
They continued to release albums into the late 1990s. Many times trying to experiment with different styles. 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.