== History ===== Lawsuit ===In 2001, the musicians filed a lawsuit against BMG because they felt that they did not get compensated fairly for their work on Dieter Bohlen productions, such as Modern Talking, Blue System, C. C. Catch, Nino de Angelo, Chris Norman, Thomas Forstner, and others.
Rolf Köhler je sodeloval z večimi različnimi izvajalci, kot naprimer Blonker, Uriah Heep, Blind Guardian, Helloween, Grave Digger, Gamma Ray, Iron Savior, Savage Circus, Tokyo, Mephistopheles, Kin Ping Meh (z Geffom Harrisonom v zasedbi), kot tudi mnogimi drugimi.