Ragnar Rosinkranz was born in Reykjavik, Iceland. His father was the National Theatre Director and his mother an opera singer. Following his mother's operatic career, he and his sister grew up in Iceland, Sweden, Germany, Italy and California. Rosinkranz began violin studies in Stockholm, Sweden at age seven with renowned violin teacher Kalman Olah. In 1980-'82 attended Maria Skolan school for musically gifted children and toured with Strangstyrkan Swedish Symphony as a soloist and as a member. At 11 years of age when the family moved to California he continued with violin studies, music theory and conducting studies at California Institute of the Arts and joined the Cal Arts Symphony.
Rosinkranz moved on from his studies to apply them to composing for film in 1996 when he wrote and produced his first full orchestra film score for the CBS Movie of the Week remake of Jimmy Stewart's classic "Harvey"
He went on to score independent films and then became a series composer the last three years of the hit CBS television drama series "The District" starring Craig T. Nelson.