I uploaded the G-Dur Praeludium BWV 568 about a year ago.
Probably it is by Bach, so it found it's place in the “regular” Bach editions.
There is a nice fuge, that is often played with it on concerts, Fuga BWV 576. Experts are not so sure about its origin, but it's got a BWV number.
It is a very nice set together: the carefree joy of playing shines in both of them. A young man's work perhaps.The fugue has a likeness to the Italian Concerto form. Could be it stems from the time Bach and Walther wrote their Italian transcriptions: who knows...
The fugue starts at 2'48''.
On the recording: if you have absolute pitch, you'll notice it is not in G but in F.
While playing the praeludium, the organ was accidentally transposed. So I had to do the same for the fugue.