Deffaa also lectures on theater and jazz. His 2007 lectures in Korea, timed to coincide with the opening of one of his plays there, were sponsored by the US State Department. Deffaa has written liner notes for albums by Chase Baird, Count Basie, Ray Brown, Ruth Brown, Miles Davis, Benny Goodman, Scott Hamilton, Dick Hyman, Jon-Erik Kellso, Tito Puente, Randy Sandke, Diane Schuur, Maxine Sullivan, and Frank Vignola.
