Of all the Bach arrangements for solo instrument that I made, this was probably the simplest, for the obvious reason that Bach conceived it for a wind instrument in the first place. The reason why I chose to transpose it (down a second), is that I am convinced that Bach’s music is best presented in a key that puts the composition at the core of the instrument’s range (but without changing the overall architecture of it!). Bach did similar transpositions in his arrangements of his own music and that of others. Since the traverso, for which the piece was composed, has the low D as the lowest note it was tempting to use a lower key than the original – because we have it on our instrument.
The version with slurs (page 8 onwards) presents how I perform the piece, and is limited to the fast movements only, to allow for some speed within the context of the music. Slurring is a skill in itself, and it is always open for debate. Therefore these slurs are to be regarded as suggestions. I would always create my personal slurring, so I suggest that you use the blank music to mark your preferred slurs and use the version with slurs only as a reference. On some instruments and instrument setups it may be possible to perform these pieces (hardly) without any slurs altogether.