double manual instruments and simplification of Bach execution?

[Derek]

Has anyone tried to play Bach on a double manual instrument of some kind? I saw the video that is hosted here at pianostreet about the double keyboard piano and was fascinated to see how much more physical convenience was lent to the player when he played a goldberg variation on it versus a single keyboard. This makes me wonder how widespread these issues are in Bach. Such as in the sinfonias for example. Sometimes it is difficult to connect an inner voice because of the distance it must travel. Yet, if I had another keyboard that was displaced in pitch, it may become easy. Has anyone experimented with this?

One situation where I'm certain two keyboards would simplify matters is in invention no 2. in c minor, there's a part where both voices are practically on top of one another, and there's a trill in one of them. It's a bit tricky to do on a single keyboard, but with two I imagine it would be easy as pie.

[j_menz]

I've played some on an organ. It is easier in those tight passages, though also raises extra questions as you have to keep a voice on the one register which can cause it's own headaches.

[iansinclair]

Interesting thought for some of the music history minded types out there -- were some of the pure keyboard Bach works (not organ works -- those are a very different thing, really) intended for two manual harpsichords?  Hadn't even thought about it, but it would make life much simpler in places, as you say!

In organ works, it is quite expected that one will use as many manuals as one has handy, plus the pedals -- but not so much to simplify fingering, as to either make voicing clear (more common in the chorales than the purely contrapuntal toccatas, preludes, fugues and the like -- although I've been known (frequently!) to use them there, too) or to achieve either dynamic or tone colour contrasts.  Much easier than changing registration in mid flight, although preselects do help a lot.  I might add that some of the more sadistic modern composers have been known to require some of the fingers in one hand to be on one manual, and some on another...