Petter Olofsson aka P9K is a Swedish bass player and all round musician. He is one of the most sought after live and session players in the northern hemisphere. 
 Since the start of his touring and recording career he has performed and collaborated with artists and bands such as Louis Cole, Genevieve Artadi, Pedro Martins, Movits!, David Binney, Kurt Rosenwinkel, KNOWER, Michał Tomaszczyk, Nine Sparks Riots, Sebastian Ågren, Tim Hagans and Norrbotten Big Band to name a few. 
 In 2016 he became a member of the Norrbotten Big Band situated in Luleå, Sweden. He has also since 2019 been a member of the world touring Louis Cole Big Band.