As I reviewed J.S. Bach’s ebullient Two Part Invention in F, BWV 779, I quickly realized that it would be an ideal springboard to teach basic essentials of keyboard harmony, not to mention, fundamentals of two-part “counterpoint.” In this endeavor, my video tutorial follows:
The extraction of ascending broken chords and descending scales (Major and minor) bounding through various keys (“modulations”) by way of “secondary dominants,” and “chromatically” efficient “diminished chords” seemed preferable to pulling Theory workbooks off the shelf for student assignment parcels. (I don’t object to a methodical Theory curriculum, but using repertoire to bring concepts to life, in a way that is digestible is an important ally to a steady diet of scales, arpeggios, chords, inversions, and their progressions around the Circle of Fifths.)
One student who is currently studying J.S. Bach’s Well-Tempered Clavier Prelude in C, BWV 846, which has a string of “broken chords” that offers an analogous opportunity to flesh out Major, minor, Diminished chord concepts, with consonant and dissonant transit through modulations, commented on my Invention 8 video that I shared with her and others: “I hope I’m the only one who was never exposed to theory and analysis, but sadly probably not.” (Many transfer pupils like this one have had little or no integration of Theory and Analysis into lessons, so their understanding of compositions previously learned has been top layered and fleeting.)
Perhaps if we, as teachers enlivened lessons with relevant infusions of analysis in living, breathing repertoire right from the start, we would not have blissful ignorance perpetuated over years.
Back to Invention 8, that attaches a pupil and teacher immersed in a mutual journey of discovery.
The main idea of BWV 779 is introduced in the “home key” of F major, that consists of a broken chord ascending, springing toward a meandering scale in descent. (Why not “block” out the rising opening measure to get a sense of the “rooted “Tonic” F Major chord) Quickly, it’s going to transform into a “First Inversion” ascent springing from the chordal THIRD, “A.” Naturally, the pupil will observe the “overlap” dimension of the main idea between the hands, but I’m currently focused on the transit of “KEYS” throughout the Invention to communicate ways in which the outflow of “modulations” provide harmonic as well as contrapuntal poignancy.
A second “idea” in measure 3 incorporates a parallel 6th relationship between voices (16th notes in both voices converge in simultaneous chatter), occurring still in the Home KEY of F but soon transported to the NEW key of C Major by way of a SECONDARY Dominant. The opening subject idea is back at this C Major juncture (broken chord up and meandering scale down), but this time the Bass introduces the broken chord and scale, which will be overlapped in the Treble.
(In my video tutorial I introduce the concept of Primary and Secondary Dominants by first playing chords on every scale degree of F Major–then demonstrating how I can take certain chords within the scale and flesh them out by placing their own DOMINANTS above them. I do the same with DIMINISHED 7th chords as smooth transits to these very chords.)
The F Major Invention No. 8 has several junctures of poignant “key change” that create ear-training opportunities.
In measure 15, a DIMINISHED 7th chord, F#, A, C, Eb unexpectedly catches the ear in a swift “modulation” to G minor. This is the very first MINOR KEY exposure within composition that’s bundled with pathos.
One of my unique discoveries this time around in my review process, is that treble sixteenths in measure 15, are a retrograde “inversion” of the measure 4, Treble sixteenths. (A, C, Bb, C compared to the main thread Measure 15: C, Bb, C, A –spread out of course, with common tone A’s)
After the G minor tonality is introduced through the Diminished 7th chord “rooted” on scale-wise 7th degree (F#), the composer makes sure to embed the descending scale dimension of the main idea through the “NATURAL” form of G MINOR–Those students who have been amply exposed to three forms of a minor scale in their Circle of Fifths journeys, will be better equipped to process this analysis. (but again the transference or infusion of this knowledge into repertoire makes it more long-lasting)
In my own teaching studio, as mentioned, I build on the study of scales, arpeggios, chords, inversions, etc. as a foundation for various repertoire journeys of discovery–knowing that shortcuts won’t work in the long term and will compromise solid learning that must be built in layers over time.
***
After the G minor modulation is imbued through measures 15-18, J.S. Bach provides a “Sequence” to the level of a D minor modulation via its 7th scale degree launch of diminished chord C#, E, G, Bb. (Naturally these “chords” are broken as the Subject introduces this format at the start of the composition) The D minor transition encompasses measures 19-20 with the voices being flipped as compared to measures 15-18.
Simultaneously, the “retrograde inversion” at this D minor juncture, that I had referenced in measure 15 is nevertheless present in measure 19 but on a new key level. (it is now G, F, G, E that appears in the BASS instead of TREBLE)–The counterpoint, as previously referenced, has been INVERTED. (meaning the “voices” are flipped)
As the Invention progresses, it needs to recapture the home KEY of F, but it’s done in a circuitous way. Where a primary DOMINANT, C, E, G, Bb appears in measure 21 (bass), it journeys to a passing D minor broken chord that suggests a DECEPTIVE CADENCE, since a D minor triad springs from the 6th degree of the F Major scale. The composer then sits on D minor for measures 22 and 23, fleshing out the MELODIC form strand of D minor in the TREBLE with raised notes B Natural, and C#, while the bass meanders to A, C#, E, G ( a SECONDARY DOMINANT in measure 23, that keeps D minor, not the HOME KEY percolating.)
The composer is not quite back to F Major, taking another side trip to the “SUB-DOMINANT” key of Bb Major. Bach slips into this Bb key by adding a seventh to the F Major chord (F, A, C, Eb) which is another Secondary Dominant (end of Measure 25)
By measure 28 he transits to the HOME KEY’s PRIMARY DOMINANT, (with a 7th), C, E, G, Bb, happily bringing the composition to its rooted TONIC conclusion. (F Major)
In summary, during the course of 33 measures, J.S. Bach has journeyed through F Major, C Major, G minor, D minor, and Bb Major giving teachers a chance to avail of an opportunity to map the ingenious path of this work with its magnificent harmonic meanderings bundled into a contrapuntal interaction. It’s a remarkable union of harmony and counterpoint that should engage students in an exciting learning process.
from Arioso7's Blog (Shirley Kirsten)
https://arioso7.wordpress.com/2021/01/10/j-s-bach-invention-no-8-a-harmonic-analysis-opportunity/
No comments:
Post a Comment