May 6, 2025
Performance Record of J.S. Bach – Invention No. 4 in D Minor, BWV 775
Overview: A performance record of Bach's Invention No. 4 in D minor (BWV 775), shared as part of Reiji's ongoing project to document and analyze all of Bach’s Inventions. This recording highlights Reiji’s early insights into underlying harmonic progressions and tonal relationships that shape the structure of the piece.
Note: All content on this page is originally explained by Reiji in Japanese. The English version is translated by AI and structured by a parent, with Reiji's final approval.
Reiji's Words and Ideas
- What first caught my attention in this piece was the way the harmony unfolds: while a typical movement from D minor would go to A minor, here it goes D minor → F → A minor.
- If we extract just the bass line of that progression, it forms D–F–A, which is the D minor triad—the tonic chord of this Invention.
- I also noticed that measures 29 to 33 use the **whole tone scale**, which creates a different kind of space and tension compared to the earlier parts of the piece.
* These are personal reflections by the performer.
| URL | https://www.youtube.com/watch?v=BK_fR9EbFRY |
|---|---|
| Reference Sheet Music |
G.Henle Verlag: J.S. BACH Inventions and Symphonies IMSLP/Petrucci Music Library , Public Domain |
| Recording date |
January 20, 2025 Performance by an 8-year-old |
AI Assistant’s Notes and Inferences
- Reiji's interpretation draws attention to a hidden structure in the harmonic movement, reinterpreting common functions in terms of bass line relationships.
- The observation about the whole tone scale from measure 29 suggests an intuitive recognition of modal coloration and structural contrast.
- These kinds of insights show a growing sophistication in Reiji’s analytical ear, especially regarding how Bach uses harmonic deviations to create expressive space within the constraints of two-part writing.