While serving with the General Staff in WWII, Lt/Col Bernard Lentz (1881-1961) developed a system of teaching close order drill whereby the soldiers not only followed the commands of the standard Infantry Drill Regulations (now FM22), they also vocalized the commands THEMSELVES. He credits Lt/Col Koehler of USMA for the original idea. Later editions noted the compatibility of his system with Butts system of calisthentics. Lentz' book, privately published, went through various editions from 1918 to at least 1957. The Cadence System is no longer practiced. However, Col. Lentz went on to command Ft. Slocum, NY in WWII, and thence emerged the Duckworth Chant, aka Sound Off aka the Jody; developed by Pvt. Willie Lee Duckworth Sr. (1924-2004), the Jody was not simply an extension of the Lentz system but Lentz recognized a kindred spirit; both of them shared copyright for Sound Off in 1951, and today the Jody is still heard as a military jogging cadence in the US Army and elsewhere.