Hartmut Geerken has been played on NTS shows including Total Stasis, with For Tesla Without Fessla first played on 6 November 2017.

Hartmut Geerken is a pianist, percussionist, author; b. Stuttgart, Germany, 15 January 1939. He started piano lessons in classical music from about age 8 and had his first solo piano recital in the age of 14 with works by Bela Bartok. Then jazz became more interesting to him and he went through a period of boogie-woogie playing. In 1967 he co-founded the Cairo Jazz Band with Salah Ragab and Edvard Vizvari and was the leader of the Cairo Free Jazz Ensemble. Later he performed in different groups with Carlos Baily, Salah Ragab, Hubertus von Puttkamer (The Cross), in duos with Michael Ranta (The Heliopolar Egg), John Tchicai and Famoudou Don Moye. He led the Rock & Free Jazz Group in Kabul/Afghanistan with Maqsud Shukurwali, Fritz Pfeiffer and others. He temporarily played with Embryo and Mondtrommler with Grace Yoon, Roman Bunka and others. He has worked with Don Cherry, Okay Temiz, Greetje Bijma, Sunny Murray, Takehisa Kosugi, Ustad Mohammed Hashem and many others.