J.S.Bach :: 'O Gott du Frommer Gott', BWV 767
Listening to Christopher Hogwood's beautiful Bach recording on clavichord, I was surprised to find Bach's Choral Partita 'O Gott, du Frommer Gott', BWV 767 in the program of the recording. I always knew this piece as one of the earlier Choral variations Bach wrote for the organ.
However, Hogwood's playing surprised me so much, that I looked the piece up, and tried it on my instrument. It was an interesting moment, since contrary to later Bach works, or later music in general, I had to search for a kind of sound that fitted to the music. It took me some hours before this piece found its way to my clavichord, but once it did, it felt so natural as if this was a piece of keyboard music.
However, played on the organ (and in some manuscripts, you find indeed an indication for 2 manuals), this is a wonderful piece of music to demonstrate many colours of the instrument, and since it doesn't require the pedal board, it works great on 18th century organs that have no separate pedal keyboard.
So, did Bach write this explicitly for the organ, or the clavichord? Certainly not explicitly, but did he have any of these two instruments in mind? Who will tell, but the approach of Hogwood became clearer to me, playing the last variation, a rather virtuoso piece, where Bach uses the terms 'piano' and 'forte', a bit as he does in the chromatic fantasy. On an organ, you would play this on two manuals, as on an harpsichord you imitate this effect equally by using two manuals, although in the latter case, this doesn't work for all passages, leaving no doubt that the Chromatic fantasy (as for all solo keyboard works written by Bach, partita's, preludes & fugues, the WTC included, are intended for the clavichord), this particular partita gives the player no need for adaptation when played on an organ. However, I was thinking, the keyboard changes in this last variation are very hard to make, much harder than on a clavichord, where the dynamic differences only require more or less weight/finger speed.
So, it felt really comfortable, and yes, who knows that Bach left out the pedal because of the clavichord?
But... let this not keep you from playing this partita on an organ!
Bonus: J.G.Walther's Musikalisches Lexicon and its connection to J.S.Bach
Certainly one of the most important early 18th century books: Musikalisches Lexicon written by J.G.Walther in 1732. I believe it would be safe to say that this entire book, with several thousands entries on musical terms and musicians, gives a quite close, if not accurate picture of the daily life and performance of that time, right in the heart of J.S.Bach's career!
And... there is an interesting description of the clavichord as well in it.
This book is a must-have. it is easy to find digitally. If you happen to know if there is an English translation, leave a link in the comment boxes, it will be of interest to others.