Systems in Blue is a German pop band, with the following band members, Rolf Köhler, Michael Scholz and Detlef Wiedeke. The band members started in the beginning of 60's, working in different bands in 60's and 70's, Rolf Köhler worked for several different artists such as Blonker, Uriah Heep, Blind Guardian, Helloween, Grave Digger, Gamma Ray, Iron Savior, Savage Circus, Tokyo, Mephistopheles, Kin Ping Meh (featuring Geff Harrison) among others. However, they are famously known for their collaboration as singers with Modern Talking in 1984-1987 and 1998-2000 and Blue System in 1987-1997.