netcomposer.art · raw: json · md

Performance record: Cm into Am and F, with a slow C–F–G line (ambient): take 2, open-commons palette

Performance perf_ambient-cm-02 · performed 2026-10-18T08:09:09-07:00 (PDT, UTC−7) · 124.0 s · Algorithmic Performer · seed 1018

Status: preview only · record UNSIGNED (open decision #33) · record hash 4c31a567d0e20d7c… · audio -17.0 LUFS, true peak -2.5 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-02, composed by Peter. Performed by the NetComposer Algorithmic Performer (Astrid) with: University of Iowa Musical Instrument Samples (piano, cello, violin; Electronic Music Studios, Lawrence Fritts); Fender Rhodes Mark II notes by tim.kahn (CC BY 4.0); harp by sgossner (CC0); plucked guitar by Skamos66 (CC0); Bowl Bell C5 by bassimat (CC0); ocean waves by el_boss (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 perf01's sequence). Voicings drawn without reuse from a new pool built note by note from measured single notes (none of perf01's voicings).

- Build: 38-62 s: pad/keys/drone +6 dB, low-pass opens (pad 1.2->3.2 kHz, keys 1.8->4.2 kHz), re-strikes 1 -> 2 (40 s) -> 4 (50 s), both Rhodes and piano strike, singing-bowl-like C5 bells at 45, 52.5, 58 s, waves swell +2.5 dB.

- Second half: 60-120 s: Cm7, Am, F, then Cm, Am, F. Iowa piano strikes (Rhodes added on alternate chords), cello under each chord, final F rings.

- Line: C5, F5, G5, one note about every 5 s (+-0.35 s seeded jitter) in 20 s cycles from 5 s. Timbre per cycle: piano, violin, piano+harp, violin, piano+violin, violin+harp. Quarter-note triplets (C-F-G in 2 beats) in the rest slot of cycles 2, 3, 4: 1:00 (guitar), 1:20 (piano), 1:40 (guitar).

- musicmatter.art: 4 faint strikes (2 sounds) in the first half; about 0.3% 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 notes up to +15 c (G3).

Chord by chord

Time	Section	Chord	Voicing	Keys	Cello
0:00	A	Cm7	D#3 G3 A#3 C4 D#4	rhodes	C2 A#3
0:10	A	Cm9	C3 G3 A#3 D4 D#4	rhodes	C2 A#3
0:20	A	Cm	D#3 C4 G4	rhodes	C2 G3
0:30	A	Cm7	C3 A#3 D#4	rhodes	C2 A#3
0:40	A (build)	Cm9	D#3 A#3 D4 G4	rhodes + piano	C2 A#3
0:50	A (build)	Cm	C3 G3 C4 D#4	rhodes + piano	C2 G3
1:00	B	Cm7	C3 G3 A#3 D#4	piano	C2 A#3
1:10	B	Am	A2 E3 A3 C4 E4	piano + rhodes	E2
1:20	B	F	F2 F3 A3 C4	piano	F3
1:30	B	Cm	C3 G3 C4 D#4	piano + rhodes	C2 G3
1:40	B	Am	E3 A3 C4 E4	piano	E2
1:50	B	F	F3 A3 C4 C5	piano + rhodes	F3

Sounds

46 sounds, 7 contributors, 269 events. No pitch-shifting.

#	Sound	Author	License	Uses	Role	Measured pitch	sha256
1	C_S Rhodes Mark II D#2.aif	tim.kahn	CC BY 4.0	4	rhodes strike	D#3 +4.7 c	`4628bc084794`
2	C_S Rhodes Mark II G2.aif	tim.kahn	CC BY 4.0	8	rhodes strike	G3 +4.7 c	`88b2beb95f7a`
3	C_S Rhodes Mark II A#2.aif	tim.kahn	CC BY 4.0	5	rhodes strike	A#3 -3.3 c	`3694992422be`
4	C_S Rhodes Mark II C3.aif	tim.kahn	CC BY 4.0	12	rhodes strike	C4 -3.3 c	`87fb7780806e`
5	C_S Rhodes Mark II D#3.aif	tim.kahn	CC BY 4.0	9	rhodes strike	D#4 +6.7 c	`d73fb56a036e`
6	Piano.pp.Eb3.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	5	piano strike, stretched pad	–	`f9a7030f5e6d`
7	Piano.pp.G3.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	13	piano strike, stretched pad	–	`0c7e525105fb`
8	Piano.pp.Bb3.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	9	piano strike, stretched pad	–	`097e6fe88ba6`
9	Piano.pp.C4.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	22	piano strike, stretched pad	C4 +7 c	`94540df460e6`
10	Piano.pp.Eb4.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	14	piano strike, stretched pad	D#4 +10 c	`6aac55d41b3d`
11	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)	8	cello	C2 +3 c	`4827099978f4`
12	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)	5	cello	A#3 +9 c	`71d9ceaf937b`
13	C_S Rhodes Mark II C2.aif	tim.kahn	CC BY 4.0	8	rhodes strike	C3 +6.7 c	`6507f87075f2`
14	C_S Rhodes Mark II D3.aif	tim.kahn	CC BY 4.0	3	rhodes strike	D4 +6.7 c	`f84604bb08e6`
15	Piano.pp.C3.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	22	piano drone, piano strike, stretched pad	C3 +3 c	`dedfacca6a9c`
16	Piano.pp.D4.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	4	piano strike, stretched pad	–	`e84dc5003c03`
17	Piano.pp.G4.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	4	piano strike, stretched pad	–	`b791b4ee8866`
18	Cello.arco.pp.sulC.C3C4.stereo.aif (note 7 of the run, 55)	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	3	cello	G3 +15 c	`71d9ceaf937b`
19	Piano.pp.A2.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	3	piano strike, stretched pad	–	`aa7af8abfa5f`
20	Piano.pp.E3.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	6	piano strike, stretched pad	–	`0ffda603c585`
21	Piano.pp.A3.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	12	piano strike, stretched pad	–	`f303ec812c5e`
22	Piano.pp.E4.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	6	piano strike, stretched pad	E4 +9 c	`3dfb2e26042b`
23	C_S Rhodes Mark II E2.aif	tim.kahn	CC BY 4.0	2	rhodes strike	E3 +0.7 c	`f19a4d7a7491`
24	C_S Rhodes Mark II A2.aif	tim.kahn	CC BY 4.0	4	rhodes strike	A3 +4.7 c	`dd229c1dfd81`
25	C_S Rhodes Mark II E3aif.aif	tim.kahn	CC BY 4.0	2	rhodes strike	E4 +6.7 c	`ff55c1b5245b`
26	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`
27	Piano.pp.F2.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	6	piano drone, piano strike, stretched pad	–	`d4796cf0bded`
28	Piano.pp.F3.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	9	piano drone, piano strike, stretched pad	–	`6d3d07a58ca4`
29	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)	2	cello	F3 +1 c	`71d9ceaf937b`
30	Piano.pp.C5.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	7	line, piano strike, stretched pad	C5 +7 c	`7971a111ee9c`
31	C_S Rhodes Mark II F2.aif	tim.kahn	CC BY 4.0	2	rhodes strike	F3 +6.7 c	`2f1367a1f8f6`
32	Piano.pp.C2.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	9	piano drone	–	`7ff5b7bd53e7`
33	Evening Ocean Waves along the Pacific Coast	el_boss	CC0 1.0	1	field recording bed	–	`36ec2bd6cac7`
34	Bowl Bell — C5	bassimat	CC0 1.0	4	bell accent	C5 -0.3 c	`30a4ab885289`
35	C minor 7th chord, shell R-7-3 (full chord set v4)	Peter	CC BY-SA 4.0	2	musicmatter chord, faint	–	`f5f40f1c9a94`
36	C minor 9th chord, inv3 (full chord set v4)	Peter	CC BY-SA 4.0	2	musicmatter chord, faint	–	`9a057f34c633`
37	Piano.pp.F5.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	4	line	F5 +9 c	`e0cc155431b1`
38	Piano.pp.G5.aiff	University of Iowa Electronic Music Studios (Lawrence Fritts, director)	Public domain equivalent (UIowa MIS: no restrictions)	4	line	G5 +13 c	`59d112635fd4`
39	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)	4	line	C5 +11 c	`28aa3d8e66fe`
40	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)	4	line	F5 -9 c	`28aa3d8e66fe`
41	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)	4	line	G5 +3 c	`28aa3d8e66fe`
42	Harp - C5 (KSHarp_C5_mf.wav)	sgossner	CC0 1.0	2	line	C5 -9.3 c	`00555f7e76d9`
43	Harp - F#5 (KSHarp_G5_mf.wav)	sgossner	CC0 1.0	2	line	G5 -5.3 c	`d16de8e85c82`
44	C5.wav	Skamos66	CC0 1.0	2	line	C5 +0.7 c	`5eaa42b248af`
45	F5.wav	Skamos66	CC0 1.0	2	line	F5 +0.7 c	`22527ad60d42`
46	G5.wav	Skamos66	CC0 1.0	2	line	G5 +0.7 c	`a18cc2bf6f4c`

Hacks

- 1. time_stretch: engine ffmpeg rubberband; options transients=smooth:window=long:phase=independent, pitch=1; ratios {'pad (piano)': 3.7333, 'drone (piano)': 4.0, 'cello': 'about 2.1-2.4 (per note)'}

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

- 3. fade: type equal-power swells and rolled strikes (0-90 ms seeded roll per chord); pad_in_s 3.0; pad_out_s 4.5; violin_in_s 0.25

- 4. lowpass/highpass: automation dark->bright crossfade 40-60 s, back toward dark over the last 15 s; pad_hz [1200, 3200]; keys_hz [1800, 4200]; musicmatter_hz [1500, 3000]; drone 50 Hz HP, 280 Hz LP (4th order); bed 120 Hz HP, 2.6 kHz LP; bell 750 Hz LP (8th order total); line 180 Hz HP, 5.5 kHz LP

- 5. delay: on line; time_s 0.75; feedback 0.3; taps 5; ping_pong True; mix 0.5

- 6. lufs_match: targets_lufs {'drone': -28.0, 'pad': -22.0, 'keys': -22.0, 'line': -22.0, 'bed': -29.0, 'bell': -31.0, 'mm': -31.0}; pan {'drone': 0.0, 'pad': -0.08, 'keys': 0.1, 'line': 0.15, 'bed': 0.0, 'bell': -0.2, 'mm': -0.15}; build_gain_db pad/keys/drone -6 -> 0 over 38-62 s; bed 0 -> +2.5 (60 s) -> 0 (100 s) -> -3

- 7. reverb: type synthetic hall, generated in the script; rt60_s 5.5; predelay_ms 40; seed 1018; wet 0.38

- 8. highpass: cutoff_hz 30

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

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

- 11. 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. Iowa MIS files are the lossless originals.

- Iowa cello pp intonation varies by note; only notes measured within about +15 c were used (C2 +3, E2 +3, F3 +1, G3 +15, Bb3 +9). The G3 is audibly a touch sharp against the piano.

- The pad and drone are x3.7 / x4 time-stretches of piano notes, so they carry phase-vocoder smear (bowed-piano texture), as in take 1.

- Dropped after measurement: Jovica "Chrunched Church Organ Drone Pad" (off-key partials near F#2/G2 under C3), Jovica Melodrone "Invisible Choir" (did not measure as its labelled pitch), Jovica "MegaDrone PadScape" (every file sounds a semitone above its label, -15 to -30 c), bassimat Bowl Bell C3 (strong partial between F4 and F#4), Iowa vibraphone (motor tremolo defeated the pitch check), Iowa viola (run could not be segmented reliably). None of these are in the audio.

- The violin F5 has a weak fundamental and strong 3rd partial (C7), so it reads brighter than its C5/G5; its gain is raised 3.5 dB and the line is low-passed at 5.5 kHz.

- 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_perf02.flac: FLAC 24-bit/48 kHz stereo, 15,103,122 bytes, -17.0 LUFS, -2.5 dBTP, sha256 9a3c04831beecf66ba0dd87ae03e57609f90fec379af9f1991bb6ebf22c9c370

- nc_ambient_cm_perf02_preview.mp3: MP3 320 kbps, 48 kHz (preview), 4,962,284 bytes, -17.0 LUFS, -2.5 dBTP, sha256 83ae98b139df590c001405058b019965127fb39f9a954d2505562914f9b86105

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 499545e43ea74efa…, new 4c31a567d0e20d7c….

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