Roots of Michał Urbaniak

Adam Andrzej Ostrowski, better known as O.S.T.R., is a Polish rapper, musician, audio engineer and record producer, famous for his freestyle rap skills, ambitious lyrics and unique beats. He graduated from the Academy of Music in Łódź, violin class. He is one of the few Polish rappers who have received professional musical education. He has collaborated with American rappers such as Evidence, El Da Sensei, Craig G, Keith Murray, Jeru The Damaja, Lil' Dap, Sadat X and Canadian producer Marco Polo. He has also collaborated with many Polish artists, including jazz musicians Michał Urbaniak, AbradAb Hades, SOFA, Fokus, DJ Deszczu Strugi, DonGURALesko, Vienio i Pelson, Fu, Pezet, Sistars and Slums Attack. He is a member of bands such as Tabasko, Skill Mega, Killing Skills, Beat Brothers and musical project POE. He is also a former member of Obóz TA and LWC. In 2013, he shared the position of art director of Męskie Granie festival with alternative rock vocalist Kasia Nosowska.

Leonard White III is an American jazz fusion drummer who was a member of the band Return to Forever led by Chick Corea in the 1970s. White has been called "one of the founding fathers of jazz fusion".