Radeck as organist of the Helligaandskirke, a post he held to his death, and also the Trinitatis Church, after marrying his widow Magdalena Sibylla in May 1685 (a practice by no means rare).
Most are intended for court performance, and one third for use in church services, but he also wrote larger works for royal ceremonies; Quis hostis in coelis and Domine in virtute were written for Charles XI's accession to the throne in 1672.
The simple counterpoint and expressive harmonic and melodic nature of these works is typically Italian, while his extravagant use of the violin and viol is rooted in the German tradition.
The manuscripts of his compositions reside in the library of the University of Uppsala, and some have been published as C. Geist: 15 Ausgewählte Kirchenkonzerte, edited by B. Lundgren, in Das Erbe deutscher Musik, 1st series, XLVIII (1960).
Lundgren (Stockholm, 1943); these are chorale preludes on "Allein Gott in der Höh sei Ehr" (All glory be to God on high); Aus tiefer Not schrei ich zu dir (From deep affliction I cry out to you), using the melody by Wolfgang Dachstein rather than the more well-known one by Martin Luther, and Gelobet seist du, Jesu Christ (Praise to you, Jesus Christ).