There are (at least) eighteen artists with this name: 1) Crossover Prog Founded in Oslo, Norway in 2013 Oak is an Oslo based quartet made up by Simen Valldal Johannessen (vocals, keyboards), Øystein Sootholtet (bass), Ole Michael Bjørndal (guitars) and Sigbjørn Reiakvam (drums, percussion, programming). All the band members are in their late 20's or early 30's and have mostly grown up in the Oslo area. They have a huge variation in their musical inspirations - everything from classical composers and singer/songwriters to electronica