[3] Wangenheim conducted the world premiere of Stockhausen's Fresco für vier Orchestergruppen on 15 November 1969.
In 1969, he was one of the founders of the Bundesjugendorchester, the national youth orchestra[3] which he shaped built as first the only conductor, with more than 160 concerts beginning on 3 August 1969 and ending in January 1984.
[6] In 1972, he was appointed professor at the Musikhochschule Köln and head of the conductors' class,[1] with students including Markus Stenz.
[8][9] His main focus was on compositions of sacred choral music without instrumental accompaniment and in Latin, which he was inspired to do in his Berlin youth while listening to Gregorian chants in a Catholic church.
[3] Wangenheim contributed the choral setting of the Easter hymn "Das ist der Tag, den Gott gemacht" to the 2013 edition of the Gotteslob hymnal.