[2] Mangelsdorff was introduced to jazz at age nine, when his mother switched to Radio Luxemburg, and he heard the voice of Louis Armstrong.

He played in the groups of Joe Klimm and Jutta Hipp, and was also a member of the Frankfurt All Stars and of the jazz ensemble of the broadcaster Hessischer Rundfunk from 1958.

[8][9] In 1966, he founded Swinging Oil Drops, with Joki Freund, Volker Kriegel, Fritz Hartschuh [de] and Günter Lenz.

[13] He played with Charles Mingus in New York[5] and performed often in the Jazzkeller (jazz cellar) in Kleine Bockenheimer Straße, Frankfurt, sometimes together with his brother, trombonist Albert Mangelsdorff.

[5] He also informed in schools about the Nazi era as a witness of the time, continuing remembrance work until old age.