netcomposer.art · raw: json · md

Performance record: The C major Prelude, harmony only (after Bach, BWV 846): take 5, forward/reverse echo

Performance perf_bwv846-take5_fwd_rev_echo · performed 2026-10-17 14:18:18-07:00 (PDT, UTC−7) · 126.4 s · Algorithmic Performer · seed 846

Status: preview only · record UNSIGNED (signing is open decision #33) · record hash bdac1317881a82dd…

Credits

- Music: Johann Sebastian Bach, Prelude in C major, BWV 846, Das Wohltemperierte Klavier I (1722). Public domain.

- Composition: The C major Prelude, harmony only, by Peter (compositions/bach_bwv846_prelude_progression.md).

- Harmonic analysis: Mark Gotham et al., When in Rome corpus (github.com/MarkGotham/When-in-Rome), CC BY-SA 4.0.

- Sounds: 28 chord strike recordings by Peter, musicmatter.art, CC BY-SA 4.0, used 74 times (each also heard reversed).

- Performer: Astrid, NetComposer Algorithmic Performer (render5_fwd_rev_echo.py). Echo idea and filter sweep requested by Peter.

Sounds used

Sound	Supplier	License	Uses	Bars
am7-bounce-2.flac	Peter	CC BY-SA 4.0	2	9
amin-bounce-5.flac	Peter	CC BY-SA 4.0	2	5
bdim7-bounce-3.flac	Peter	CC BY-SA 4.0	2	14
c7-bounce-4.flac	Peter	CC BY-SA 4.0	2	20
c7-bounce-6.flac	Peter	CC BY-SA 4.0	2	32
cdim7-bounce-3.flac	Peter	CC BY-SA 4.0	2	28
cmaj-bounce-26.flac	Peter	CC BY-SA 4.0	6	1, 4, 35
cmaj-bounce-28.flac	Peter	CC BY-SA 4.0	4	25, 29
cmaj-bounce-32.flac	Peter	CC BY-SA 4.0	2	19
cmaj-bounce-34.flac	Peter	CC BY-SA 4.0	2	15
cmaj7-bounce-6.flac	Peter	CC BY-SA 4.0	2	8
csus4-bounce-4.flac	Peter	CC BY-SA 4.0	4 (layer ×4)	26, 30
d7-bounce-4.flac	Peter	CC BY-SA 4.0	2	10
d7-bounce-6.flac	Peter	CC BY-SA 4.0	2	6
dm7-bounce-1.flac	Peter	CC BY-SA 4.0	2	17
dm7-bounce-3.flac	Peter	CC BY-SA 4.0	4	2, 33
dmin-bounce-4.flac	Peter	CC BY-SA 4.0	2	13
dsharpdim7-bounce-4.flac	Peter	CC BY-SA 4.0	2	22
edim7-bounce-5.flac	Peter	CC BY-SA 4.0	2	12
fmaj7-bounce-1.flac	Peter	CC BY-SA 4.0	2	21
fmaj7-bounce-4.flac	Peter	CC BY-SA 4.0	2	16
g7-bounce-2.flac	Peter	CC BY-SA 4.0	8	18, 24, 27, 31
g7-bounce-3.flac	Peter	CC BY-SA 4.0	2	34
g7-bounce-6.flac	Peter	CC BY-SA 4.0	2	3
gmaj-bounce-30.flac	Peter	CC BY-SA 4.0	2	7
gmaj-bounce-32.flac	Peter	CC BY-SA 4.0	2	11
gsharpdim7-bounce-4.flac	Peter	CC BY-SA 4.0	2	23
gsus4-bounce-3.flac	Peter	CC BY-SA 4.0	4	26, 30
28 sounds			74

No time-stretch and no pitch change. Each file's decoded audio is sample-identical to the FLAC on musicmatter.art (PCM md5 checked); sha256 values are in the record JSON.

Hacks chain

1. Reverse echo: each strike also played reversed, starting 0.10 s after it and swelling to a peak 80 ms before the next strike; 6 dB under the forward voice, −3 dB shelf above 4 kHz, ducked where it would mask the next attack

2. Reverb: synthetic hall, generated in the script (no external IR), RT60 2.6 s, 22 ms predelay, seed 846, 40% wet (reverse voice 50%)

3. Low-pass sweep: 24 dB/oct, 500 Hz → 20 kHz over the first 60 s, then back down to 600 Hz by the end

4. Tail: 3 s fade

5. Loudness: two-pass linear, −14 LUFS / −1 dBTP ceiling, mp3 measured −13.9 LUFS, −1.0 dBTP

Tempo: 69 BPM, broadening over bars 33–35 (+4%, +10%, +18%). Two strikes per bar.

Known compromises

- Bars 26, 30: Layered substitution: G7sus4 = Gsus4 + Csus4/G (no 7sus4 recording)

- Bars 28: G pedal under F#dim7 not carried (G is not a chord tone of any dim7 take)

- Bars 34: C pedal under G7 not available

License & attribution

CC BY-SA 4.0. Every input is public domain or CC BY-SA 4.0, with no NC or ND inputs.

Ready to paste:

“The C major Prelude, harmony only (after Bach, BWV 846)”, NetComposer Performance perf_bwv846-take5_fwd_rev_echo, composed by Peter after J.S. Bach (public domain), with harmonic analysis from When in Rome by Mark Gotham et al. (CC BY-SA 4.0, github.com/MarkGotham/When-in-Rome). Performed by the NetComposer Algorithmic Performer (Astrid) from 28 chord recordings by Peter (musicmatter.art, CC BY-SA 4.0). Licensed CC BY-SA 4.0, https://creativecommons.org/licenses/by-sa/4.0/

Files: take5_fwd_rev_echo.wav sha256 056951cdceb3b703… · .mp3 sha256 9ecc6f9e1a6e2a24…

Amendment

2026-10-17T19:29:52-07:00: contributor display name changed from Petrus to Peter (Peter Semmelhack) for netcomposer.art, at his request. Nothing else changed. Previous record hash d17c38ba79ba9451…, new bdac1317881a82dd….