Fifteenth studio album by the Brazilian metal band. The concept album is based on numerology, the number four and its significance as depicted on Quadrivium. As with 'Machine Messiah' (2017), the band went to Sweden to work with producer Jens Bogren for the recording of 'Quadra'. The word is Latin, meaning 'four ways'. Based on this, the band divided the 12-track album into four sections of three songs each. The first section features thrash metal songs, based on the classic Sepultura sound; the second section is inspired by the groove-percussion oriented sound the band explored in 'Roots' (1996); the third part includes songs inspired by 'Iceberg Dances' from 'Machine Messiah'; and the fourth section features slow-paced and melodic tracks, similar to the song 'Machine Messiah'.