This is my entry for the Secrets of Organ Playing, week 99. I play the newest publication on my website: Kirchhoff's prelude to the choral "Freu dich sehr, o Meine Seele", transcribed and newly set from manuscript Mus, Ms 40037 owned by the Staatbibliothek Berlin.
Judging by the length Kirchhoff's chorale prelude to "Freu dich sehr, o meine Seele" is his most ambitious compositon contained in manuscript Mus. Ms. 40037. It consists of 4 variations on the choral melody and concludes with a chorale harmonization.
The first variation is a two part canon of the choral melody. The second variation is written in a trio like texture and has the chorale melody in the tenor voice. In the third variation the soprano voice plays a richly embellished version of the chorale melody. The melody is perhaps a bit difficult to discern between all the sixteenth notes, nevertheless, all melody notes are there. In the fourth variation the soprano voice plays again the chorale melody, only this time in plain simple notes. The pedals play a pizzicato like bass line, while the tenor voice fills in the harmonies with a simple sixteenth notes motif.
In the manuscript the accompaniment in the third variation is written as figures bass. To make playing of this variation a bit more easy I've written a realization of this figured bass. The final choral harmonization is also written with a figured bass. I did not write a realization of this harmonization. In my performance I leave out the final harmonization of the choral melody and play only yhe four variations. The result is that the last 7 bars are played by the left hand alone. It is not often that the left hand has the main role, and certainly not as a solo ánd conclusion of a composition.
The recording was done with the Hauptwerk software and the sampleset, made by Sonus Paradisi, of the Schittger organ in the St. Martini-kerk, Groningen (http://www.sonusparadisi.cz/en/organs/netherlands/groningen-st-martini.html).
Score available here: http://partitura.org/index.php/gottfried-kirchhoff-freu-dich-sehr-o-meine-seele