Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Obsession is the fourth album of Blue System. Was published in 1990 by BMG Ariola and produced by Dieter Bohlen. The album contains 10 new tracks. Blue System was a German pop group that was founded by Dieter Bohlen in 1987 after the break-up of Modern Talking. The group consisted of Dieter Bohlen (composer, producer, vocals), Rolf Köhler (vocals), Michael Scholz (backingvocals), Detlef Wiedeke (backingvocals). On stage: Joachim Vogel (rhythm-guitar), Jeanne Dupuy and Frank Otto (drums). In 1988 Frank Otto was replaced by Michel Rollin. After that in 1991 a new keyboardist joined - Achim Striben. In 1992 Dirk Sauer, Rene Engelman and Fritsch Wolfgang joined the group, while Joachim Vogel left.