Born in Pisa, Italy. Began scoring films in 1994 with the British comedy short MODELS REQUIRED. Subsequent scoring credits include THE SHEEP THIEF and I WENT DOWN (both 1997), THE FUNERAL OF THE LAST GYPSY KING and SOUTHPAW: THE FRANCIS BARRETT STORY (both 1999), BEING CONSIDERED and PANDAEMONIUM (both 2000), THE WARRIOR (2001), THE VISITOR and IN THIS WORLD (both 2002), I CAPTURE THE CASTLE, SEPTEMBER, THE BYPASS and CHEEKY (all 2003), THE BROTHERS GRIMM, SHOOTING DOGS, PRIDE & PREJUDICE, SAUF LE RESPECT QUE JE VOUS DOIS / BURNT OUT, OPAL DREAM and V FOR VENDETTA (all 2005), SHROOMS, THE RETURN and WE ARE TOGETHER (all 2006), GOODBYE BAFANA, ATONEMENT, FAR NORTH and THE BRAVE ONE (all 2007), HIPPIE HIPPIE SHAKE and THE SOLOIST (both 2008), and ALL QUIET ON THE WESTERN FRONT 3-D (announced for 2009). Marianelli was invited to join A.M.P.A.S. in 2006.  Nominated for Achievement in Music (Original Score) 2005: PRIDE & PREJUDICE  Best Achievement in Music (Original Score) 2007: ATONEMENT 2 nominations, 1 Award