In 2016, Duda took time away from both Riverside and Lunatic Soul to record a collaborative session with guitarist Maciej Meller of Quidam and drummer Maciej Gołyźniak of Sorry Boys. From this point on, Duda divided his time between Riverside and Lunatic Soul, releasing Lunatic Soul II in November 2010, Impressions a year later, and Walking on a Flashlight Beam in October 2014. Built around arrangements that included no guitars, Lunatic Soul's self-titled debut album appeared in October 2008, and rose to number 23 on the Polish album charts. In 2008, looking for an outlet for his compositions that didn't suit Riverside, he recorded a solo album under the name Lunatic Soul.

In 2002, Duda became a founding member of Riverside, a group whose music fused elements of progressive rock and heavy metal. Born in Poland on September 25, 1975, Duda's musical career began in the '90s when he joined the heavy prog band Xanadu, appearing on their album Wczorajsze ślady.

A progressive rock band whose approach embraces electronic and new age influences, Lunatic Soul is a project led by Mariusz Duda, also known as the bassist and singer with the group Riverside.

Lunatic soul bandcamp