In mid-to-late 60s, Conny attended new-music courses at the Rheinische Musikschule in Cologne, taught by Karlheinz Stockhausen, Luciano Berio, Henri Pousseur, and Earle Brown.

[2] Plank began producing albums and working as a sound engineer in the late 1960s and became involved in the underground music scene which was spreading outwards through Germany from Berlin.

In 1983, Moebius & Plank also recorded the album Ludwig's Law using an Emulator, an early form of sampling keyboard that enabled them to duplicate other instruments without having musicians to play them.

[3] During the eighties, Plank remained in high demand with the new generation of electronic pop and new wave artists, including Devo, the Meteors from the Netherlands (Hunger in 1980 and Stormy Seas in 1981), Hunters & Collectors from Australia ( The Fireman's Curse in 1983 and The Jaws of Life in 1984) the Fred Banana Combo, Ultravox (Systems of Romance, Vienna and Rage in Eden), Echo & the Bunnymen, Freur, Killing Joke, the Tourists (Luminous Basement) and Eurythmics (In the Garden).

He also worked on pop and rock productions with artists such as Scorpions, Clannad, Play Dead, and Gianna Nannini (Latin Lover, Sogno Di Una Notte d'Estate, Tutto Live and others, also credited for music).

[7] Plank became sick while touring South America with Dieter Moebius, Arno Steffen and Detlef Wiederhoeft performing music from Ludwig's Law.

Some of Plank's last work, before his death in 1987 from laryngeal cancer in Cologne, was the recording of concerts on Eurythmics' Revenge tour, and samples used on the NED Synclavier on their Savage album.

[3] Plank's studio established at his home on the southern outskirts of Cologne continued to be run by his widow Christa Fast and their son until her failing health and the general change in the music business forced them to offer its contents for sale in May 2006.

Conny's hand-built mixing desk was bought by English producers David M. Allen and Mark Ralph and transported to England.

[citation needed] The mixing desk was initially installed at Club Ralf, the private studio of producer Mark Ralph, where he used it to record and mix a range of work including all or parts of "In Our Heads" and "Why Make Sense" by Hot Chip, "Right Thoughts, Right Words, Right Action" by Franz Ferdinand and "Communion" by Years & Years.

[9] Plank and the bands he worked with in West Germany had a strong influence on mainstream rock artists, some of whom were able to popularize aspects of his production technique and his distinctive approach.