Bach: WTC I Prelude and Fugue No. 20 in a, BWV 865 (D. Jacques Way Harpsichord)

West Point Organist Craig Williams plays the twentieth prelude and fugue in Johann Sebastian Bach's Well-Tempered Clavier, Volume I. The prelude in a minor is a fast piece with running passages in 9/8 time, taking on the character of a courante. Typical of Bach's method, the running passages alternate between the left and right hand, using chords to frame the harmony played against the fast scales. Bach was almost unique among baroque composers with his ability to have the bass play continuo parts, framing the root of the various chords with arpeggios, but then seamlessly move the bass part into taking up a dialogue imitating the fast passages with the upper voices. The fugue is massive, beginning with a feminine subject on the second eighth note of the first 4/4 measure and moving up sequentially to a group of four sixteenth notes and two eighth notes, then dropping down several intervals to a rest. This leads to the final phrase also beginning on an offbeat which is the pickup eighth note to the third measure in the subject, consisting of two groups of four sixteenth notes and then four eighth notes. The subject is busy and rhythmically complex, spanning three measures which might be seen as an asymmetrical grouping in 4/4 time. After the four voices play out in the exposition, with the tenor voice entering last, there begins a new exposition with the subjects and answers in inversion. The characteristic dropping eighth notes in the second measure now leap upward, a striking pattern which becomes very recognizable to the ear as the fugue plays out. Similar to the subject patterns of the C Major fugue, BWV 846, these subjects - original and inverted - lend themselves easily to stretto, presented in layers for the most part after the expositions of the original and inverted subjects. Like many of his largest free fugues (the massive organ fugues from BWV 538 and 542 come to mind), the voices are built up to intense cadences at which time Bach thins out the texture to two or three voices, either high or low, and then rebuilds the intensity from there. This happens four times within this fugue's vast structure. Toward the end, the intensity builds to a full diminished chord using more than four voices, marked by a fermata. This invites the performer either to take a very long pause or maybe add a brief cadenza (the option taken here), before moving into the bold harmonically dense coda which finally plays out over a long pedalpoint consisting of low A. This also evokes the idea of the large organ fugues, because the low A cannot be held by the hands while playing all the passages above it. High A is then struck in the closing measures, with the idea that it is to be sustained above the moving passages finishing the piece. It is impossible to hold the resulting multiple voices at the end with only two hands, so the notes must be imagined as a full texture is maintained to the end. The artistic license taken in this performance creates the sense of the organ pedal bass note held to the end by reiterating the low A in full octaves, while taking on the main notes heard in the A Major triad forming the closing chord. The preludes and fugues in Bach's Well-Tempered Clavier do not call for notes below bass C, but playing the bass A octave gives a satisfying sense of finality to such a massive fugue, taking advantage of the greater manual compass on the Flemish harpsichord.
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#baroquemusic
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#welltemperedclavier
0:00 Prelude
1:21 Fugue