Musik in Geschichte und Gegenwart: "Orgelchoral"
Orgelchoral in: Musik in Geschichte und Gegenwart (MGG)
Excerpt:
"... J. S. Bach's work was essentially based on the types of chorale arrangements developed in Central Germany...
Meanwhile, the traditional types of chorale arrangements changed fundamentally under Bach's hands due to the new importance that was now attached to the contrapuntal voices that confront the chorale melody, whether they were freely designed or derived from the material of the cantus firmus..."
(Prof. Dr. Arno Forchert, Rudolf Innig)