Around the middle of the 17th century a new musical genre appeared in Central Germany and Stettin (Szczecin) – the “actus musicus”. These are compositions that were equally rooted in the Protestant and Jesuit school dramas of the 16th century and in the historia compositions, the dialogues and the Italian rappresentationi, and that are marked by their specific textual disposition permitting particular dramatic and musical realizations. [...]
The emergence of this new genre may be understood as the attempt to integrate the combined traditions of school plays, sacred historias, the dialogue and the dramatic element of the Italian opera and oratorio into the German Protestant church music by providing them with a new form.
Johann Schelle led the genre to great artistic expressiveness, even though he excluded its dramatic aspect. The term “actus musicus” appeared for the last time in the compositions of Abraham Petzold, Johann Kuhnau and Friedrich Wilhelm Zachow. When Erdmann Neumeister’s cantata texts appeared, the composers’ interest immediately turned to the new form of the madrigalian cantata.
By developing the dramatic textual disposition of Heinrich Schütz’ Historia der fröhlichen und siegreichen Auferstehung […] Jesu Christi (1623) the genre gained lasting musicological significance. Presented in Stettin in 1649, the Actus musicus de Divite et Lazaro by Andreas Fromm was already through-composed and became paradigmatic for the writing of oratorios in Germany. In the preface to his actus Fromm gives precise instructions about how to place the performing forces.
In his Actus musicus de Filio perdito Georg Calmbach (1612–1676) sets to music the parable of the prodigal son (Luke 15,10–24). Following the formal disposition with three choirs, the action unfolds on three levels: the report of the narrator (chorus II), the biblical plot (chorus I) and the voices of two basses, Godfather and a four-part chorus admonishing the lost son for his behavior (chorus III). […]
(Dr. Klaus-Jürgen Gundlach, translation by Stephanie Wollny)