# The C major Prelude, harmony only (after Bach, BWV 846)

**Composer of this Composition:** Peter · **License out:** CC BY-SA 4.0
**Meter:** 4/4 · **Tempo:** quarter note ≈ 69 BPM (tolerance ±3) · **Length:** 35 bars, about 2 minutes
**Directionality:** 0.3 (stay close to the chords; textures are welcome if the harmony is right)
**Allowed transforms:** trim, gain, fade, time_stretch

## Prose

Bach's C major Prelude without its notes, keeping only its harmony. There's one chord per bar, and the
chord changes on every downbeat and never in the middle of a bar. Each bar should sound like the same
gesture played twice, because Bach states every figure twice per bar. Keep it even and unhurried,
evenly lit, with no swells. The harmony does all the work.

It opens at home and wanders a little, first to the dominant (bars 1–11). Then it darkens through borrowed
diminished colours (bars 12–14) and comes home again (15–19). From bar 20 it leans toward the subdominant
and slides chromatically into a long dominant pedal on G (bars 24–31). This is the tension of the piece:
let it feel suspended and keep it unresolved. Bars 32–35 sit on a C pedal, and the very last bar is a
single held C major that is allowed to ring. A slight broadening over the last three bars is welcome.

Keep the harmony clear and the space modest: a room, not a cathedral.

## Chord anchors (one per bar)

| Bar | Chord | Bar | Chord | Bar | Chord |
|---|---|---|---|---|---|
| 1 | C | 13 | Dm/F | 25 | C/G |
| 2 | Dm7/C | 14 | Bdim7/F | 26 | G7sus4 (→ G7) |
| 3 | G7/B | 15 | C/E | 27 | G7 |
| 4 | C | 16 | Fmaj7/E | 28 | F#dim7/G |
| 5 | Am/C | 17 | Dm7 | 29 | C/G |
| 6 | D7/C | 18 | G7 | 30 | G7sus4 (→ G7) |
| 7 | G/B | 19 | C | 31 | G7 |
| 8 | Cmaj7/B | 20 | C7 | 32 | C7 (C pedal) |
| 9 | Am7 | 21 | Fmaj7 | 33 | Dm7/C |
| 10 | D7 | 22 | F#dim7 | 34 | G7/C |
| 11 | G | 23 | Bdim7/Ab | 35 | C (held, ringing) |
| 12 | C#dim7/G | 24 | G7 (G pedal begins) | | |

Slash chords name the bass. Bars 24–31 sit on a G pedal and bars 32–35 on a C pedal. A Performer that can't
match a bass note may let it go, but it should keep the chord.

*Structure (spec §5.6):* `4/4 · 69 BPM · [1 bar C][1 bar Dm7/C][1 bar G7/B] … [1 bar C] · 35 sections · loops: 1`

## Credits

- **Music:** Johann Sebastian Bach, Prelude in C major, BWV 846, from *Das Wohltemperierte Klavier* I (1722). Public domain.
- **Harmonic analysis:** Mark Gotham et al., *When in Rome* corpus,
  `Corpus/Keyboard_Other/Bach,_Johann_Sebastian/The_Well-Tempered_Clavier_I/01/analysis.txt`,
  https://github.com/MarkGotham/When-in-Rome. License: **CC BY-SA 4.0**. The Roman numerals were converted
  to absolute chord symbols for this Composition, so the anchors above are an adaptation and are shared
  under the same license.


*Amended 2026-10-17T19:29:52-07:00 for netcomposer.art: composer display name shown as Peter (Peter Semmelhack). The harmony is unchanged.*