Kammerton

Pitch to which orchestral instruments in Germany were tuned in the 17th–18th centuries. It was lower, by a whole tone or more, than the Chorton (choir-pitch) used for church organs, and it was for this reason that Johann Sebastian Bach, in his Leipzig cantatas, transposed the organ parts down a tone in order to make them agree with the orchestra. The transposition applied only to the organ parts; the orchestral parts could be used as they stood.