Geffen is presently vice president for artistic administration at the Saint Louis Symphony Orchestra, where he collaborates closely with music director David Robertson in all aspects of artistic planning. In June 2006 the Saint Louis Symphony was recognized with the ASCAP Morton Gould Award for Innovative Programming for the 2005-06 season.
At the SLSO, Geffen frequently participates in pre-concert lectures and discussions, as does Ara Guzelimian at Carnegie.
Before his post in St. Louis, Geffen was artistic administrator for the New York Philharmonic for over four years and prior to that, associate artistic administrator for the Aspen Music Festival and School for several years.
In Aspen, Geffen hosted a weekly radio show. He has also adjudicated Metropolitan Opera National Council Auditions for the past three years.
Geffen was born in Cape Town, South Africa, and raised in Newport Beach, California. He began studying viola as a child and pursued performance studies at the University of Southern California.