Telemann's prelude to the choral "Herr Jesu Christ, dich zu uns wendt" appears in no less then three different catalogues. As it is nowadays known to be a composition of Telemann, it apeats in the catalogue of Telemann's composition, the Telemann Werke Verzeichniss. And because it was once thought to be possibly a composition by Johann Sebastian Bach, it appears in the second appendix to the catalogue of Bach's compositions, BWV Anhang II. And Emans included it in his list of spurious Bach compositions.
It is a strange composition in which the choral melody is played in half notes in the pedals and unisono in eigth notes in the left hand part. Perhaps Telemann meant to offer a choice to play eithe the variant wiuth the long notes or the variant with the eigth notes. But this is just a supposition, as in the manuscript it is written out on three staves, indicating al three parts should be played.
The right hand plays a lifely accompanying part in rapid sixteenth notes that consists of lots of broken chords and scale passages. It is a bit reminiscent of a piano exercise by Carl Czerny, even though Telemann was long dead when Czerny was born. What puzzles me most is that this composition was once thought to be possibly composed by Bach. The style is not very Bach-like and the unisono treatment of the choral melody in both left hand part and pedal part is not like Bach at all.
The recording was done with the Hauptwerk software and the sampleset, made by Sonus Paradisi, of the Schnittger organ in the St. Martini-kerk, Groningen (https://www.sonusparadisi.cz/en/organs/netherlands/groningen-st-martini.html).
Score available here: http://partitura.org/index.php/georg-philipp-telemann-herr-jesu-christ-dich-zu-uns-wendt-twv-318-bwv-anh-ii-56-emans-98