Here is the first video in a new series exploring the difficult questions that arise when arrangers must decide whether or not to make a change to Bach’s original.
When dealing with instruments that are as different from one another as the violin and the guitar, there are times when one might want to add a bass note or an inner voice. There may be a gap in a line, there may be an extra voice, or Bach may have created an effect that works on the violin but is not possible, in the same way, on the guitar.
Forkel, Bach’s first biographer, states that, according to Bach himself, arranging Vivaldi’s concertos had “taught him how to think musically.” Similarly, we can say that the process of arranging Bach’s music has given us many insights into his musical thinking, by encountering questions and problems of a different nature than those we face when simply playing from a score.
For example, there is a passage in the Ciaccona that alternates between three and four voices; whenever the melody goes below the violin's first string or above its fourth, Bach is limited to three strings and therefore must lose either the tenor or the alto voice. Those voices are possible on the guitar, and so an arranger may choose to add them in. However, in our edition we did not fully alter that passage to four voices because it would have changed the aesthetic. Part of Bach's genius lies in his ability to take a concession and make it into a strength; here, the three voice sections tend to be more quiet and introspective––so, in that way, they help the rhetoric.
This video introduces these types of questions and many more.