Helmut Köllen joined Triumvirat in time to lend his bass, voice, and composition skills to this German progressive rock band’s two most famous albums: Spartacus and Illusions on a Double Dimple. In spite of overwhelmingly critical acclaim, Triumvirat was left as an opener for acts like Grand Funk Railroad in Europe and Supertramp in the US. Köllen soon departed to pursue a solo career. Whether his death in 1977 was a suicide or an accident is anyone’s guess. He died in his car from monoxide poisoning while listening to a demo tape of his songs with the garage door closed.