[1][2] Flaten played electric bass in local funk trio Neon (1990), and studied on the Jazz program at Trondheim Music Conservatory (1992–94).
He attended the Bugge Wesseltoft's album New Conception of Jazz (1995–96), and from 1995 he was a member of two successful groups, the Paul Bley inspired trio Close Erase, with recording 1995 1998, 2001 and 2006.
[1][2] In the winter of 1995–96 Flaten moved to Oslo and this led to many new involvements, like Acidband, SAN: Song (1996), Oslo Groove Company, YoungLove, and not least the super trio with Petter Wettre (1996–), usually just called The Trio: Meet the locals (1998), In color (1999) and Mystery unfolds (2001), Tour de force with Petter Wettre/Dave Liebman (2000).
Moreover, his authoritative bass have been listening to records with Sigurd Køhn (1996), Eivind Aarset (1997), Jazzmob (1998), Bugge Wesseltoft's Sharing (1998), Moving (2001) and Live (2000–02), Didrik Ingvaldsen (2000), two albums with the band School Days (2000 and 2001), seven albums with The Thing, a trio with Mats Gustafsson and Paal Nilssen-Love (2001), Live at Blå (2003), Action jazz (2005), Now and forever (2005), Immediate sound with Ken Vandermark (2007) and Bag it!
[4] A record with Bugge Wesseltoft New Conception of Jazz released in 2004, the same year as he was awarded Vitalprisen at Kongsberg Jazzfestival.