Buttstett wrote a fine prelude to "Vom Himmel kam der Engelschar". It start with a solo line that goes up in rapid notes and then descends in a flowing line to the lower g. Perhaps Buttstett had the same idea as Bach in BWV 607 and wanted to depict the angels flying down from above. Fact is that in the rest of the piece the accompaniment flows up and down and it easy to image the angels hovering above the fields and the shepherds. The choral melody is played twice. Once in the soprano voice, and once in the bass voice.
The recording was done with the Hauptwerk sofware and the sample set of the Bader-organ in the Walburgiskerk in Zutphen by Sonus Paradisi (http://www.sonusparadisi.cz/en/organs/top-selection/zutphen-virtual-organ-model.html).
Free score available here: http://partitura.org/index.php/johann-heinrich-buttstett-vom-himmel-kam-der-engelschar/