Lunatic Soul is a progressive rock side-project, founded by Riverside vocalist and bass guitarist Mariusz Duda in 2008. Originally conceived to allow him to explore genres outside of rock, the project was described by Duda in 2014 as progressive, ambient, oriental and electronic. Lunatic Soul has released seven albums to date. The most recent album, Through Shaded Woods, was released on November 13, 2020, and has been described by Duda as 'more folky' than previous releases.

Riverside are a Polish progressive rock band from Warsaw. They were founded in 2001 by friends Mariusz Duda, Piotr Grudziński, Piotr Kozieradzki and Jacek Melnicki, who shared a love for progressive rock and heavy metal, although Duda, the main lyricist and composer of the band, was originally a fan of electronic, ambient, experimental music, like Radiohead, Massive Attack, Dead Can Dance, Tangerine Dream, Peter Gabriel, and later on, prog rock like Pink Floyd, Rush, Tool, Marillion, as well as thrash metal. Riverside can be described as a blend of atmospheric rock and metal elements, resulting in a sound similar to that of Porcupine Tree, and Pain of Salvation.