Bach, Johann Sebastian : Fantasie g-moll BWV 920
Work Overview
Genre：fantasy
Total Playing Time：7 min 50 sec
Copyright：Public Domain
Commentary (2)
Author : Asayama, Natsuko
Last Updated: May 1, 2008
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Author : Asayama, Natsuko
A lengthy work consisting of six parts. Its very length is both a characteristic and perhaps a flaw of this piece. Although it does not adopt the clear T-F-T-F-T structure of traditional German toccatas and fantasies, the second, fourth, and fifth sections begin with imitation between both hands. On the other hand, arpeggiated chords are indicated by half notes at various points, such as at section breaks, requiring an improvisatory treatment. Commonplace idioms are frequently employed and juxtaposed, such as two-hand arpeggios spanning the full width of the keyboard and perpetuum mobile passages based on sequential imitation. A certain sense of redundancy cannot be denied.
However, in the chords and harmonic progressions used—even if many cannot be called typical of Bach—bold sounds with a sense of color occasionally emerge as if shining through. Regardless of its authenticity, it is a work from which considerable performance effect can be expected.
Author : Ooi, Kazurou
Last Updated: September 14, 2023
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Author : Ooi, Kazurou
This is the Fantasia in G minor. What is particularly essential for this fantasia is 'directionality'. If this type of piece is played flatly, it becomes truly drawn out and results in an unclear performance. To achieve directionality, harmonic analysis is indispensable. For instance, regarding the arpeggiated chords beginning on the third beat of measure 3, there are a total of 15 chords. These chords can be divided into three groups:
- First: The initial five chords
- Second: The six chords from the sixth chord onwards
- Third: The final three chords
Let's examine the first group. When moving from the first chord to the second, the middle note D in the right hand ascends to E-flat. When moving from the third chord to the fourth, the middle E-flat in the right hand descends to D, but the middle note of the left-hand chord ascends from C to D. In terms of harmony, writing C-D in both the right and left hands would result in the forbidden 'parallel octaves,' so Bach avoided this by writing the right hand descending from E-flat to D. However, in reality, the progression C-D remains in the listener's ear, similar to the left hand (as the left hand also contributes). Then, when moving from the fourth chord to the fifth, the lowest C in the right hand descends to B natural in the subsequent chord.
Following this movement, we observe the melodic contour D-E-flat-C-D-B natural. This implies that the second chord is at the highest point, and from there, the tension gradually decreases, reaching the fifth chord. Consequently, we should increase the volume most when moving from the first to the second chord, then gradually decrease it, ultimately progressing to the tonic (main chord).
The second group is analyzed similarly. Now, let's compare the first and second groups. The second group clearly exhibits higher tension, so this contrast should be expressed through dynamics. Furthermore, if we assume that the third group possesses the highest tension, this approach enables us to impart directionality to all 15 of these chords. By conducting such analysis and imbuing all sections with directionality, a flat performance can be avoided. This serves as a crucial hint for performing this piece.