Bach’s music is usually held in high esteem as a model of musical perfection. In fact, a quote, attributed to Schoenberg, goes "There is no greater perfection in music than in Bach!" The Suites for Solo Cello, BWV 1007-1012, are also extensively played and studied, not only as cornerstones of the unaccompanied cello repertoire, but also as examples of harmony and self-accompaniment in unaccompanied string instrument writing.
A little-known fact, however, is that a close examination of the suites throws up several imperfections in Bach’s writing, which take the form of unplayable chords. Some of the chords have notes which are spaced too far apart; some others have awkward finger placement. From a performer’s point of view, they are chords which require special handling, or just a pain in the ***.
From a compositional viewpoint, however, they are mistakes. Which means to say that if a composition student wrote like that, he would be marked wrong; and if a professional composer wrote those chords, the cellist would probably need a word with him. That’s right. Bach made mistakes too.
The most likely explanation I can think of for these mistakes is because Bach was documented to have played the violin and viola, but it was doubtful whether he actually played the cello, and could have transferred his violinistic instinct to the Cello Suites with less than desirable results.
Note that Suites 5 and 6 are not discussed in this article, whereas the first four are written for C-G-D-A tuning and hence are examined in their original context.
Mistake 1: Suite no. 3 in C Major, Prelude, b. 80
Unplayability rating: 1.5/5
This chord is actually not difficult to execute. It is just a mistake compositionally because of the need to use the same finger on the highest and lowest strings. The obvious way around it is to roll the chord.
Mistake 2: Suite no. 2 in D Minor, Gigue, bb. 19 and 49
Unplayability rating: 2.5/5
Unplayability rating: 2/5
These are two mistakes in the same vein. In both instances, holding the dotted crotchet for its full value is clearly impossible, so the cellist will instinctively (and rightly) cut it short, but even then, the interval of a tritone between E and Bb makes for very awkward finger placement. The top passage is slightly harder than the bottom one.
Mistake 3: Suite no. 2 in D Minor, Menuet I, b. 2
Unplayability rating: 4/5
From the first minuet of the same suite comes this hand-breaker in the second bar. This is the first of the three examples of chords with notes which are spaced too far apart. Playing this chord probably requires replacing of the fingers when spreading the chord, most likely 4/1->2/1. The Fournier edition gives the fingering of this chord as 4/2/1, on the C, G and D strings. So the bottom C is played with a 4th finger harmonic on the C string. I’d also contemplated using thumb on the Bb but… naaaaaaah.
(Fun fact: I usually fake this chord by changing one of the notes. Not many people can tell. =P)
Mistake 4: Suite no. 4 in Eb Major, Sarabande, b. 30
Unplayability rating: 3/5
Another example of a chord whose notes are spaced too far apart. However, problem is easily solved by truncating the top E flat, since it’s a tie-over.
Mistake 5: Suite no. 4 in Eb Major, Prelude, b. 60
Unplayability rating: 4.5/5
I saved the best for last. This chord is a mistake whichever way you look at it, and it is Bach’s most severe, hand-breaking brain fart in his Cello Suites. It’s related to the third example, but even worse. Mischa Maisky actually used thumb on the top Bb, though I haven’t seen how other cellists do it. I wonder how period performers cope with this chord, given that 1) it’s difficult to use thumb on a cello with no endpin and 2) cellos in the 18th century tended to be even bigger than they are now.
BONUS - Parallel 5th: Suite no. 4 in Eb Major, Sarabande
One may argue that the D changes the chord and hence it isn’t a parallel 5th, or one may argue that it’s an anticipation and hence it is. What do you think?