Pete, thanks for that link, I really do like the Mozart interpretation on the clavichord, also because it shows the dynamic range capabilities.
My guess is that JSB simply 'loved this instrument above all' because it was the most advanced thing available at the time.
No, maybe just the opposit. The clavichord is probably the simplest keyboard construction even at Bach's time. However it is said to be the keyboard construction with the most expressive possibilities. And that is what attracts me - I never heard a clavichord live or played on one. I will try anytime in a shop where they sell the kits to build an own clavichord (unfortunately, the kit costs about 4.000,- Euro all together, very expensive, but with good quality wood and sonor quality (so it is said). Bach was a collector of plenty much keyboard instruments and had access to a church organ to play on. But at night he loved to play the clavichord, and also his son C.P.E. Bach prefered to clavichord too. So there MUST be something interesting about that, and I expect it is the very direct tone control. Surely Bach could let the thing sing, maybe only soft, but sing - and that is what all good performers tried in history and present on all instruments. The clavichord seems not the worst choice for that.
Since the sound determining brass part is directly connected to the key, I expect that there is no limit regarding soft playing, one can hit the key in very slow motion. So (without having any practical experience) I expect huge dynamic capabilities because of that unlimited part regarding soft playing. Furthermore the pitch can be changed through applying pressure on the keys (maybe through wiggling on the keys too, I dunno?). So from my side it is the range of expression what gets my attention.
It is also said that a clavichord needs very exact execution and finger control because of that direct one-to-one connection between key and string contact. Also the sound when the key is released can be controlled. Anyhow that all sounds interesting to me.
What I don't understand is why any pianist with a gorgeous state-of-the-art Steinway grand would desire to dabble around on a clavichord. You going to wear a wig as well Olaf ?
You think wearing a wig would be better as running around without hairs?
Ok, I know it was a joke...
Regarding Bach, I really do think that this kind of music is very well suited to be played on more percussive but nevertheless expressive sounding instruments like the clavichord. I did play lately some WTC items on my digital keyboard with clavichord sound, sounded interesting to me. My Steinway will ever remain for Chopin, that's of course for sure!
However I really can imagine that clavichord playing can create a certain intime atmosphere. I like the idea to be able to play late at night on a real instrument (no digital one), without the need to shut windows because of neighbours and without respect for children to not interfere their sleep. Whoever has a piano in the living room knows what I am speaking about. Have to try out!