His primary teachers have been Warren Baker, Mark Lawrence, Frank Crisafulli, M. Dee Stewart and Joseph Alessi.

[3] From 1992-2002 he was a member of the Seattle Symphony, where he participated in dozens of recordings, performing on trombone, euphonium and bass trumpet.

He was the principal trombone for many of Seattle Opera's productions of Richard Wagner's Der Ring Des Nibelungen.

Ellefson has authored articles on Wagner and Bruckner in the Journal of the International Trombone Association[5] and in the Brass Player's Cookbook.

[6] Ellefson is married to Deborah Rutter, former president of the John F. Kennedy Center for the Performing Arts in Washington, D.C