While I had always been aware that the Subject, or main idea, had been inverted at various points in the composition; pieced out or abbreviated; then mimicked back and forth between the hands in characteristic "counterpoint," I hadn't realized how J.S. Bach borrowed the first four notes of the subject, and had these blown up as longer note values at various junctures. (Augmentation) I'd also noticed that fragments of the opening subject were inverted and streamed in sequential groups. While Bach's enlistment of technical devices was intrinsic to his style, the beauty of his music and its divine inspiration were the core of his musical creations

In this video tutorial I carefully journeyed through each voice, noting form, harmonic movement, and phrasing. Finally I played through the Invention, fleshing out voices and nuances as I went along.

http://www.youtube.com/watch?v=MzEX4IGR8dU

Baby step practicing:

Often piano students of all levels want to study a particular piece and achieve instant results in the shortest time possible.

But in truth, any learning process, going back to our earliest year of life is marked by passages and transitions in baby steps. We couldn't walk before rolling over in our cribs, then sitting up, crawling, and achieving vertical balance.

Beginners have the exciting, parallel challenge of studying a new "language," with its vocabulary of musical symbols, meters, clefs, (Bass and treble) while building coordination skills in each hand alone, and then combining two hands at a time. Their pieces gradually advance from simple melodies to more complex forms involving chords and counterpoint (interweaving voices) And while learning primer level pieces might seem substantially removed from studying the more advanced literature (compositions by Bach, Mozart, Beethoven, Chopin, et al) the same attitude of patient, parceled out practicing in layers, from the ground up, applies.

The student who has advanced far enough in his/her studies to play a Bach Two Part invention, with its characteristic dialog of two conversing and overlapping voices, will know this composition more thoroughly and satisfactorily by following each separate line of music, phrase by phrase in slow motion. (The tempo is bent to accommodate the learning process) It's back to the baby step approach.

Having the patience to experience a piece in its expanded, enlarged, form by playing it very slowly, line by line, is worth the time invested. It gives ample space to feel the shape and contour of the phrase; as well as the spatial, interval relationships between notes, while practicing in a fingering that best realizes the smooth flow of music.

To overload ourselves with all the details of notation all at once when learning a new piece, reading it down over and over without getting to the heart and soul of it in a patient, graduated process is probably the biggest reason why compositions reach a certain plateau and do not ripen over time.

Therefore, slow, deliberate, but sensory enlightened practicing is recommended for students who want to improve their playing and obtain fluidity.

More two part Inventions:
http://www.youtube.com/watch?v=UIOewMxAUZQ
http://www.youtube.com/watch?v=l5exU_FbGvY