netcomposer.art · raw: json · md

Performance record: Cm into Am and F, with a slow C–F–G line (ambient): take 3, rolled piano and forest air

Performance perf_ambient-cm-03 · performed 2026-10-18T11:18:20-07:00 (PDT, UTC−7) · 124.0 s · Algorithmic Performer · seed 2026

Status: preview only · record UNSIGNED (open decision #33) · record hash 6c3ac089018ea076… · audio -17.0 LUFS, true peak -2.4 dBTP

The Composition (Peter, verbatim)

Composition - 2 mins - half Cm, Cm7, Cm9. Second half Cm7, Am, F.

Performance - ambient vibe, no harsh tones, randomly alt between Cm chord structure in first half, build to second half and follow Cm, Am, F pattern. Don't rush it. Over the top of it all play a slow C, F, G pattern. Include an occasional triplet

Composition file · audio, MP3 · audio, FLAC · raw JSON

Credits

- “Cm into Am and F, with a slow C–F–G line (ambient)”, NetComposer Performance perf_ambient-cm-03, composed by Peter. Performed by the NetComposer Algorithmic Performer (Astrid) with: University of Iowa Musical Instrument Samples (piano, cello, violin, alto flute; Electronic Music Studios, Lawrence Fritts); Fender Rhodes Mark II notes by tim.kahn (CC BY 4.0); acoustic guitar notes by allan764 (CC BY 3.0); “pineforest 1-3bft winter” by klankbeeld (CC BY 4.0); harp by sgossner (CC0); guitar G5 by Skamos66 (CC0); soft rain on leaves by deleted_user_3544904 (CC0), all on Freesound; and two chord sounds by Peter from musicmatter.art (CC BY-SA 4.0). Licensed CC BY-SA 4.0, https://creativecommons.org/licenses/by-sa/4.0/

How it was played

- First half: 0-60 s. Six chords, type drawn at random from {Cm, Cm7, Cm9} (no immediate repeat, all three heard, last not Cm7, not the take-1 or take-2 sequence). Voicings drawn without reuse from a new pool (none used in takes 1 or 2). Keys: slow upward Iowa piano rolls (150-450 ms per chord, seeded).

- Build: 38-62 s: pad/keys/drone +6 dB, low-pass opens (pad 1.1->3 kHz, keys 1.7->4 kHz), re-strikes 1 -> 1 (40 s, Rhodes joins) -> 2 (50 s); harp C5, G5, low piano C3, harp C5 plucks at 44.6, 49.6, 54.6, 58.3 s; the pine-forest wind crossfades to soft rain from 56 s.

- Second half: 60-120 s: Cm7, Am, F, then Cm, Am, F. Rhodes strikes on every chord, Iowa piano rolls added on alternate chords, one re-strike per chord, Iowa cello under each chord (Bb3 / E2 / F3), cello drone C2 (F3 under the F chords), final F rings.

- Line: C5, F5, G5, one note about every 5 s (+-0.4 s seeded jitter) in 20 s cycles from 7 s. Timbre per cycle: guitar, piano, guitar + alto flute (C only), violin, harp + piano, guitar + violin. Every line source is level-matched to the same 1.5 s RMS. Quarter-note triplets (C-F-G in 2 beats) in the rest slot of cycles 1, 3, 4: 0:22.1, 1:01.9, 1:22.1 (piano, harp + piano, piano).

- musicmatter.art: 2 faint strikes (2 sounds: Cm7 at 0:46, Am at 1:16); about 0.1% of pre-reverb energy

- Pitch: Every pitched sound chosen by NC measurement (pYIN / FFT peak), not by label. Accepted within about +-15 cents (Iowa cello G3 +15 is not used in this take; allan764 F5 +15 c is the outer edge).

Chord by chord

Time	Section	Chord	Voicing	Keys	Cello
0:00	A	Cm	D#3 G3 C4 G4	piano	–
0:10	A	Cm9	G3 D4 D#4 A#4	piano	–
0:20	A	Cm7	D#3 A#3 D#4 A#4	piano	–
0:30	A	Cm9	D#3 G3 A#3 D4	piano	–
0:40	A (build)	Cm7	C3 D#3 G3 A#3	piano + rhodes	–
0:50	A (build)	Cm9	C3 A#3 D4 D#4	piano + rhodes	–
1:00	B	Cm7	C3 A#3 D#4 G4	rhodes	A#3
1:10	B	Am	A2 A3 E4 C5	rhodes + piano	E2
1:20	B	F	F2 A3 C4 F4	rhodes	F3
1:30	B	Cm	G3 C4 D#4 C5	rhodes + piano	A#3
1:40	B	Am	A3 C4 E4 A4	rhodes	E2
1:50	B	F	F3 C4 F4 A4	rhodes + piano	F3

Sounds

46 sounds, 8 contributors, 214 events. No pitch-shifting.

#	Sound	Author	License	Uses	Role	Measured pitch	sha256
1	Piano.pp.Eb3.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	5	piano roll	D#3 +5 c	`f9a7030f5e6d`
2	Piano.pp.G3.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	7	piano roll	G3 +7 c	`0c7e525105fb`
3	Piano.pp.C4.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	4	piano roll	C4 +7 c	`94540df460e6`
4	Piano.pp.G4.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	3	piano roll, stretched piano pad	G4 +7 c	`b791b4ee8866`
5	C_S Rhodes Mark II D#2.aif	tim.kahn	CC BY 4.0	6	rhodes strike, stretched Rhodes pad	D#3 +4.7 c	`4628bc084794`
6	C_S Rhodes Mark II G2.aif	tim.kahn	CC BY 4.0	9	rhodes strike, stretched Rhodes pad	G3 +4.7 c	`88b2beb95f7a`
7	C_S Rhodes Mark II C3.aif	tim.kahn	CC BY 4.0	12	rhodes strike, stretched Rhodes pad	C4 -3.3 c	`87fb7780806e`
8	Piano.pp.D4.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	5	piano roll	D4 +9 c	`e84dc5003c03`
9	Piano.pp.Eb4.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	7	piano roll	D#4 +10 c	`6aac55d41b3d`
10	Piano.pp.Bb4.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	4	piano roll, stretched piano pad	A#4 +7 c	`54f008f00816`
11	C_S Rhodes Mark II D3.aif	tim.kahn	CC BY 4.0	6	rhodes strike, stretched Rhodes pad	D4 +6.7 c	`f84604bb08e6`
12	C_S Rhodes Mark II D#3.aif	tim.kahn	CC BY 4.0	12	rhodes strike, stretched Rhodes pad	D#4 +6.7 c	`d73fb56a036e`
13	Piano.pp.Bb3.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	7	piano roll	A#3 +5 c	`097e6fe88ba6`
14	C_S Rhodes Mark II A#2.aif	tim.kahn	CC BY 4.0	12	rhodes strike, stretched Rhodes pad	A#3 -3.3 c	`3694992422be`
15	Piano.pp.C3.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	7	piano pluck, piano roll	C3 +3 c	`dedfacca6a9c`
16	C_S Rhodes Mark II C2.aif	tim.kahn	CC BY 4.0	10	rhodes strike, stretched Rhodes pad	C3 +6.7 c	`6507f87075f2`
17	Cello.arco.pp.sulC.C3C4.stereo.aif (note 10 of the run, 58)	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	2	cello	A#3 +9 c	`71d9ceaf937b`
18	C_S Rhodes Mark II A2.aif	tim.kahn	CC BY 4.0	9	rhodes strike, stretched Rhodes pad	A3 +4.7 c	`dd229c1dfd81`
19	C_S Rhodes Mark II E3aif.aif	tim.kahn	CC BY 4.0	6	rhodes strike, stretched Rhodes pad	E4 +6.7 c	`ff55c1b5245b`
20	Piano.pp.A2.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	3	piano roll, stretched piano pad	A2 +5 c	`aa7af8abfa5f`
21	Piano.pp.A3.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	2	piano roll	A3 +7 c	`f303ec812c5e`
22	Piano.pp.E4.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	2	piano roll	E4 +9 c	`3dfb2e26042b`
23	Piano.pp.C5.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	11	line, piano roll, stretched piano pad	C5 +7 c	`7971a111ee9c`
24	Cello.arco.pp.sulC.C2B2.stereo.aif (note 5 of the run, 40)	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	2	cello	E2 +3 c	`4827099978f4`
25	Piano.pp.F2.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	1	stretched piano pad	F2 +3 c	`d4796cf0bded`
26	Piano.pp.F4.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	3	piano roll, stretched piano pad	F4 +13 c	`5a5bf948aa37`
27	Cello.arco.pp.sulC.C3C4.stereo.aif (note 5 of the run, 53)	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	5	cello, cello drone	F3 +1 c	`71d9ceaf937b`
28	Piano.pp.A4.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	3	piano roll, stretched piano pad	A4 +11 c	`86d6230bfd83`
29	C_S Rhodes Mark II F2.aif	tim.kahn	CC BY 4.0	2	rhodes strike, stretched Rhodes pad	F3 +6.7 c	`2f1367a1f8f6`
30	Piano.pp.F3.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	1	piano roll	F3 +7 c	`6d3d07a58ca4`
31	Cello.arco.pp.sulC.C2B2.stereo.aif (note 1 of the run, 36)	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	9	cello drone	C2 +3 c	`4827099978f4`
32	pineforest 1-3bft winter 130102_00.flac	klankbeeld	CC BY 4.0	1	field recording bed (A)	–	`227a518e1f9a`
33	Ambience-Leaves-Wind-Soft-Rain-Apeldoorn-Netherlands-ccm41-ccm8.wav	deleted_user_3544904	CC0 1.0	1	field recording bed (B)	–	`0f781cd54fd6`
34	Harp - C5 (KSHarp_C5_mf.wav)	sgossner	CC0 1.0	4	harp pluck, line	C5 -9.3 c	`00555f7e76d9`
35	Harp - F#5 (KSHarp_G5_mf.wav)	sgossner	CC0 1.0	3	harp pluck, line	G5 -5.3 c	`d16de8e85c82`
36	C minor 7th chord, position 5, root 8va (full chord set v4)	Peter	CC BY-SA 4.0	1	musicmatter chord, faint	–	`a389975e0b97`
37	A minor chord, position 6, inv2 8va (full chord set v4)	Peter	CC BY-SA 4.0	1	musicmatter chord, faint	–	`83d989b0139a`
38	33-C5.flac	allan764	CC BY 3.0	3	line	C5 +9 c	`68974b69098e`
39	38-F5.flac	allan764	CC BY 3.0	3	line	F5 +15 c	`3093f4e35d74`
40	G5.wav	Skamos66	CC0 1.0	3	line	G5 +0.7 c	`a18cc2bf6f4c`
41	Piano.pp.F5.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	5	line	F5 +9 c	`e0cc155431b1`
42	Piano.pp.G5.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	5	line	G5 +13 c	`59d112635fd4`
43	AltoFlute.vib.ff.C5.stereo.aif	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	1	line	C5 +1 c	`ab2bbed5437a`
44	Violin.arco.pp.sulD.C5B5.stereo.aif (note 1 of the run, 72)	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	2	line	C5 +11 c	`28aa3d8e66fe`
45	Violin.arco.pp.sulD.C5B5.stereo.aif (note 6 of the run, 77)	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	2	line	F5 -9 c	`28aa3d8e66fe`
46	Violin.arco.pp.sulD.C5B5.stereo.aif (note 8 of the run, 79)	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	2	line	G5 +3 c	`28aa3d8e66fe`

Hacks

- 1. time_stretch: engine ffmpeg rubberband; options transients=smooth:window=long:phase=independent, pitch=1; ratios {'pad (Rhodes)': 2.3333, 'pad (piano fill)': 3.7333, 'cello': 'about 2-3 (per note)', 'drone (cello)': '15 s pieces, tiled every 11 s'}

- 2. gain: type decay flatten (300 ms RMS follower, max +20 dB); applies_to ['pad']

- 3. gain: type level match: every line source to the same 1.5 s RMS before its gain

- 4. fade: type equal-power swells; seeded upward piano rolls 150-450 ms; Rhodes strikes 0-50 ms; pad_in_s 3.0; pad_out_s 4.5; violin_in_s 0.25

- 5. lowpass/highpass: automation dark->bright crossfade 40-60 s, back toward dark over the last 15 s; pad_hz [1100, 3000]; keys_hz [1700, 4000]; musicmatter_hz [1500, 3000]; drone 45 Hz HP, 300 Hz LP (4th order); bed 150 Hz HP, 3 kHz LP; plucks 2.5 kHz LP; line 180 Hz HP, 5.2 kHz LP

- 6. delay: on line; time_s 1.0; feedback 0.32; taps 4; ping_pong True; mix 0.5

- 7. lufs_match: targets_lufs {'drone': -27.0, 'pad': -21.5, 'keys': -22.0, 'line': -22.0, 'bed': -30.0, 'pluck': -30.0, 'mm': -32.0}; pan {'drone': 0.0, 'pad': 0.06, 'keys': -0.1, 'line': 0.12, 'bed': 0.0, 'pluck': 0.22, 'mm': 0.15}; build_gain_db pad/keys/drone -6 -> 0 over 38-62 s; line -1.5 dB in the first half

- 8. reverb: type synthetic hall, generated in the script; rt60_s 6.0; predelay_ms 45; seed 2026; wet 0.4

- 9. highpass: cutoff_hz 30

- 10. lowpass: type gentle 9 kHz blend (40%)

- 11. tail: rule music ends 120 s, 4 s fade, file 124 s

- 12. loudness: method ffmpeg loudnorm two-pass, linear; target_lufs -17; ceiling_dbtp -1.5

Known compromises

- Freesound sounds are HQ previews (lossy); originals need OAuth, not set up. The two field recordings (klankbeeld 173031, 398425) are long files, so only the first 6,000,001 bytes of each HQ preview were fetched with an HTTP Range request; the hashes cover exactly those bytes. Iowa MIS files are the lossless originals.

- The pad is a x2.3 time-stretch of Rhodes notes (Iowa piano fills Bb4/D3/D4/F4 etc. that the Rhodes set lacks, at about x3.7), and the drone is a stretched Iowa cello note, so both carry some phase-vocoder smear.

- allan764 G5 (467689) was rejected: its pitch track was unstable (+11 to +114 c across windows, FFT peak +6 to +9 c). The guitar G5 is Skamos66 399476 (CC0, +0.7 c), whose preview is only 1 s long, so guitar G notes are short plucks.

- sgossner 373573 is titled "Harp - F#5 (KSHarp_G5_mf.wav)"; it measures G5 -5 c and is used as G5.

- Dropped after measurement for this take: Iowa alto flute F5 (+33 c) and G5 (+35 c), Iowa flute non-vib (C5 +17 c with wide spread, G5 measured an octave low), Iowa Bb clarinet (unstable), Iowa piano Ab3 / G2 / D5 (no stable voiced frames in the pp file). Only the alto flute C5 (+1 c) is used, doubling the line C in cycle 3.

- Iowa MIS terms are "freely available ... used for any projects, without restrictions", not a formal CC0/PD dedication; treated as public-domain equivalent, credited anyway.

Outputs

- nc_ambient_cm_perf03.flac: FLAC 24-bit/48 kHz stereo, 16,720,815 bytes, -17.0 LUFS, -2.4 dBTP, sha256 b5ee81fc72694d93c3851fd54d5bdddb807c01d28aaf883bc8d10ac9ef73b66e

- nc_ambient_cm_perf03_preview.mp3: MP3 320 kbps, 48 kHz (preview), 4,962,284 bytes, -17.0 LUFS, -2.4 dBTP, sha256 0f1c66c003fc569245dc6dd732e806d464e9ee9e47db3b2a2fb813353b13bd04

Amendment

2026-10-18T11:23:17-07:00: Contributor display name changed from 'Petrus' to 'Peter' (Peter Semmelhack) for netcomposer.art, at his request. No audio, input, setting or other field changed. Previous record hash 98424febdbea24f6…, new 6c3ac089018ea076….

License: CC BY-SA 4.0, https://creativecommons.org/licenses/by-sa/4.0/