[3] In 1936, he then went to work for Martin Block on the Make Believe Ballroom radio show at Milton H. Biow's WNEW in New York City.
[3] World War II interrupted his career and he served in a Signal Corps film unit of the United States Army Air Corps where he wrote the war documentary films, Memphis Belle: A Story of a Flying Fortress (1944)[3] and Thunderbolt (1947), both directed by then-Major William Wyler.
He continued to work with Wyler after the war, taking important production roles in The Best Years of Our Lives, The Heiress, Carrie, Detective Story, and Roman Holiday.
In 1951, Koenig founded Contemporary Records, where he produced albums by such jazz figures as Sonny Rollins, Ornette Coleman, Art Pepper, Barney Kessel, Benny Carter, Phineas Newborn, Jr., Hampton Hawes, Harold Land, Woody Shaw, Shelly Manne, Ben Webster, Ray Brown, Andre Previn, Howard McGhee.
Teddy Edwards, Red Mitchell, Victor Feldman, Helen Humes, The Curtis Counce Group Sonny Simmons, Art Farmer, Leroy Vinnegar, The Lighthouse All-Stars and others.