1. Invention No. 13: two active partners
Purpose: practice technique through the exchange of musical ideas. Preparation: read sixteenths steadily and work on each line separately. This A-minor excerpt avoids treating Bach as a RH melody with a passive LH accompaniment.
The RH begins with a sixteenth rest; the LH sounds on the downbeat. Count that first subdivision rather than beginning both hands together. During the second half of measure 1, the LH takes up the running figure while the RH has eighth notes.
Learn the exchange, not just the hands
- Play the RH alone, including its opening rest and the quarter rest at the end of measure 2.
- Play the LH alone. Hold its first A in the higher register for the full quarter note; the opening bass A is only an eighth.
- Combine one half-bar at a time, then overlap the segments. Listen through the point where the sixteenths pass to the LH.
- Shape the two bars as a phrase fragment. Avoid a new accent every time the figure changes hands.
No fingering is imposed on this excerpt. Choose and test a route for the broken-chord shapes at a slow tempo before speeding up. The G♯s are written alterations, not a direction to sharpen every G throughout the piece.
Source: Allen Garvin, Mutopia 59, public-domain transcription from Bach-Gesellschaft. Notes, rests, and registers retained; layout changed; no new articulation, fingering, or dynamics.
2. Recognize a familiar figure in a new place
Measures 7–8 of the same invention bring the running figure into a different harmonic setting. Compare the contour with the opening rather than assuming that the same written fingers will fit every transposition.
Keep listening during rests
In measure 8 the LH plays two eighths, rests for a quarter, and then begins its next figure after a sixteenth rest. Count the silence as carefully as the notes. The RH continues through this gap; it must not wait for the LH to re-enter.
Play the LH with the RH downbeats only as a temporary timing reduction. Then restore the RH notes, keeping the LH entry in its original place. Do not turn the rest into extra preparation time by slowing the pulse.
Make a fingering comparison
Choose one short running shape in the opening and its counterpart here. Write a provisional fingering for each. Compare their destinations, black keys, and the notes that follow. Keep a fingering when it serves the new context; change it when the next movement requires a better position.
Play each choice slowly several times, then at a moderate flowing tempo. A route that works only when every note is separately positioned is not yet secure. Avoid changing several fingers at once during the same attempt.
Check: sing either line while playing the other, within a comfortable vocal range or by humming its contour. Then play both and retain that sense of two partners. Source and adaptation scope are the same as for measures 1–2 on the preceding page.
3. Use repertoire as a focused technical study
Bach’s music offers specific coordination problems inside complete phrases. Choose one problem at a time rather than repeating a whole invention and hoping that independence will emerge automatically.
| Passage printed in these chapters | Technical question | A useful reduction |
|---|---|---|
| Invention No. 13, measures 1–2 | Does the pulse survive the transfer of sixteenths? | One running line plus the other hand’s beat points |
| Invention No. 13, measures 7–8 | Does a voice re-enter accurately after rests? | The returning line plus a sparse pulse in the other hand |
| Sinfonia No. 11, measures 1–7 | Do long upper notes survive middle-voice movement? | Upper and middle voices only |
| WTC I C-major Fugue, measures 4–7 | Can a new bass entry emerge without losing inner lines? | Bass paired with one existing voice at a time |
Restore every omitted note before deciding that the passage is secure. A reduction is a way to diagnose and learn the texture, not a replacement arrangement for the final performance.
Choose articulation deliberately
The excerpts here do not add blanket legato or staccato rules. Start by hearing the motive, meter, note lengths, and relationship between voices. Compare two plausible degrees of separation at an easy tempo, and listen for clarity and phrase direction.
Do not assume that every eighth note should be detached or every sixteenth connected simply because of its duration. Editorial slurs and fingerings in other editions are useful evidence, but distinguish them from the source and from your own practice markings.
Practice record: note the excerpt, the one problem being addressed, the reduction used, and what improved when the full texture returned. Keep a musical goal such as a clear entrance or an uninterrupted inner line alongside any tempo target.