Born in Canada, Rittenhouse spent her early years in South Africa. She began her music training at the age of six and debuted her own music compositions at age ten. At age thirteen, she won a music scholarship for study at the University of South Africa, where she had auditioned on both piano and violin.
Rittenhouse began her teaching career at Walla Walla College, now University, in the fall of 1945, a year after graduating summa cum laude with a music degree from the University of Washington. She taught for one year before going to Atlantic Union College, where she taught violin and piano until the early 1950s.
She founded the New England Youth Ensemble (NEYE) in 1969 with a group of five students and made their first international trip in 1973 to the World Youth Congress in Edinburg, Scotland.
In 1994, the NEYE became the resident orchestra of Washington Adventist University and has since continued to enjoy widespread critical acclaim. Under her direction the NEYE has performed both nationally and internationally for numerous world leaders.
Always valuing education on all levels, Rittenhouse developed the NEYE Carnegie Scholars Program,a unique mentorship program that brings scholar members of the NEYE to the stage of Carnegie Hall.This experience also enabled the members to perform under the direction of numerous well known conductors, including John Rutter, with whom the NEYE has held a long-standing friendship.