Copper Glow

The note that produced it

On this track: “Carry the glow”, “light-years to go”, “golden record”, and the opening lines; the only song with words.

“I want each to be a mosaic assemblage of the tracks, never the whole track. Each a separate video experiment to see the samples, get the groove. Aim for 1–2 minutes per track.”

“A different attempt and technology for each Afterlight song / music video experiment”: readable as embers from their spectrograms, as Gaussian splats of places.

What was made

The sung lines’ own spectrum as a ribbon of light; its strongest partials break off as embers into the wind, with porch lights and windows from the archive behind.

Light-years in a second-hand song 0:00 · carry the glow 0:46 in sixteenths · the room goes gold 1:07 · golden record 2:17

On the cut before

“Carry the glow”, “light-years to go”, “golden record”, and the opening lines; the only song with words.

On this cut

“The mix of all of them … is crowded and the video is too dark.” Think like the One-Note Soul Prism genome: one radiant strike refracted by pitch over raw boom-bap; and like a sunset set by the sea, embers rising into stars, sun glitter, caustic nets of light.

Sample map

Every sound placed in the 1:39 study, 68 events by layer, coloured by the track it was cut from. The bars under the map are the whole source tracks; the lit spans are the parts actually used (approximate: stretched and frozen samples are counted by where they start).

The recipe

The function that composed this study, exactly as it ran.

def copper():
    """the only voice: 'light-years in a second-hand song', 'carry the glow', 'the room goes gold', 'golden record', chopped over the song's own groove"""
    n = 'copper'; P = 3.75; m = Mix(100)
    V1 = cut(n, 0.0, 7.5)                     # Light-years in a second-hand song / Light-years and I'm still holding on
    V2 = cut(n, 46.0, 60.0)                   # Oh-oh-oh carry the glow / light-years to go
    V3 = cut(n, 67.0, 81.0)                   # Neighbors ... room goes gold
    GR = cut(n, 137.0, 139.4)                 # golden record
    # opening: the first line slowed and lowered, alone, in a long room
    low = resample(V1, 0.8)
    m.put('vox', low, 0.5, 0.8, n, 0.0, 'lightyears-slow'); m.put('ember', ember(low, 10, 0.6), 0.5, 1, n, 0, 'tail')
    t = 0.5 + len(low) / SR
    G = snap(n, 85.0); PG = period(n, G, 128.0, 8)
    m.put('loop', sweep(loop(n, G, PG, 2), 300, 15000), t, 1.0, n, G, 'groove'); place_kicks(m, n, G, PG, t, 2); t += 2 * PG
    m.put('vox', V1, t, 1.0, n, 0.0, 'lightyears'); m.put('loop', loop(n, G, PG, 2), t, 1.0, n, G, 'groove'); place_kicks(m, n, G, PG, t, 2); t += 2 * PG
    # stutter: 'carry the glow' cut into sixteenths over the groove
    m.put('loop', loop(n, G, PG, 4), t, 1.0, n, G, 'groove'); place_kicks(m, n, G, PG, t, 4)
    cg = steps(n, 46.0, PG, 16)
    play_pattern(m, 'chop', cg, [0, 1, 0, 1, 4, 5, 4, 5, 8, 9, 10, 11, 8, 8, 8, 8], t, PG / 16, 0.9, n, 46.0, PG, reps=2)
    m.put('vox', V2[:int(2 * PG * SR)], t + 2 * PG, 1.0, n, 46.0, 'carrytheglow'); t += 4 * PG
    m.put('loop', loop(n, G, PG, 4), t, 1.0, n, G, 'groove'); place_kicks(m, n, G, PG, t, 4)
    m.put('vox', V3, t, 1.0, n, 67.0, 'roomgoesgold'); t += 4 * PG
    # break: the groove leaves; 'golden record' echoes into the dark
    m.put('echo', echo(GR, PG / 4, 0.62, 10, 0.85), t, 0.9, n, 137.0, 'goldenrecord')
    m.put('bed', freeze(cut(n, 60, 66), 8), t, 0.5, n, 60, 'freeze'); t += 2 * PG
    m.put('loop', loop(n, G, PG, 4), t, 1.0, n, G, 'groove'); place_kicks(m, n, G, PG, t, 4)
    m.put('vox', V2[int(2 * PG * SR):], t, 1.0, n, 46.0 + 2 * PG, 'lightyearstogo')
    play_pattern(m, 'chop', steps(n, 0.0, PG, 16), [0, None, 0, None, 2, 2, None, 3, 0, None, 0, 1, 2, 3, None, None], t + 2 * PG, PG / 16, 0.6, n, 0.0, PG, reps=2)
    t += 4 * PG
    m.put('loop', tapestop(loop(n, G, PG, 1), 1.4), t, 1.0, n, G, 'tapestop')
    m.put('vox', resample(V2[-int(3 * SR):], 0.85), t + 0.4, 0.8, n, 57.0, 'outro')
    m.put('ember', ember(V2[-int(3 * SR):], 20, 0.9), t + 0.4, 1, n, 57.0, 'tail')
    m.duck(['loop', 'bed'], 0.5, release=0.22)
    return m

The picture technique

class VoiceEmbers:
    """the sung lines as a glowing ribbon of their own spectrum crossing the frame; the strongest partials break off as embers into wind,
    and the archive's porch lights and windows show faintly through the glow"""
    def __init__(s, ctx, cats=('lam', 'nig', 'han', 'chi'), seed=9):
        s.c = ctx; s.clips = [clip_frames(i, 320, 240, 12, 10) for i in footage(cats, 6, seed)]; s.emb = Embers(40000, 11)
        s.vox = [e for e in ctx.events if e['layer'] in ('vox', 'chop')]
    def frame(s, t, dt):
        c = s.c; img = np.zeros((H, W, 3), np.float32)
        cl = s.clips[int(t / 8) % len(s.clips)]; f = up(cl[int(t * 12) % len(cl)].astype(np.float32))
        L = f.mean(2); img += (np.clip(L - 0.5, 0, 1) ** 1.5)[..., None] * np.array([1.0, 0.7, 0.4]) * 0.3
        vox = c.e('vox', t) + c.e('chop', t) * 0.7
        # the ribbon: last 5 s of the spectrum, right to left; vocal band only
        cols = int(5 * c.melfps); i1 = int(t * c.melfps); i0 = max(0, i1 - cols)
        band = c.mel[18:90, i0:i1]
        if band.shape[1] > 2:
            rib = cv2.resize(band[::-1], (int(W * band.shape[1] / cols), 300), interpolation=cv2.INTER_LINEAR)
            canvas = np.zeros((300, W), np.float32); canvas[:, W - rib.shape[1]:] = rib
            age = np.linspace(1, 0, W)[None]                    # left is older
            v = canvas ** 2 * 2.2 * (0.3 + 0.7 * (1 - age)) * (0.5 + 1.0 * min(1, vox * 1.5))
            img[210:510] += v[..., None] * thermal(0.3 + 0.65 * canvas)
            # the newest column's peaks leave as embers
            col = band[:, -1]; pk = np.nonzero((col > 0.58) & (np.r_[0, np.diff(col)] > 0) & (np.r_[np.diff(col), 0] < 0))[0]
            if len(pk):
                ys = 210 + (1 - pk / band.shape[0]) * 300; n = len(pk) * 6
                s.emb.emit(np.full(n, W - 30, np.float32) + np.random.default_rng(int(t * 99)).normal(0, 10, n), np.repeat(ys, 6).astype(np.float32), vx=-180, vy=-30, T=1.0, life=3.5, spread=25)
        kk = c.kick(t, 0.2)
        s.emb.step(t, dt, wind=(-160, -25), gust=kk * 0.8, buoy=-30); img += s.emb.draw(t, 1.0, 0.07)
        for e in c.events:
            if e['tag'] == 'goldenrecord' and 0 <= t - e['t'] < 2.5:
                a = t - e['t']; img += (np.exp(-((np.sqrt((XX - W / 2) ** 2 + (YY - H / 2) ** 2) - (60 + a * 260)) / 4) ** 2) * (1 - a / 2.5))[..., None] * GOLD
        return img + gaussian_filter(img, (6, 6, 0)) * 0.35

Files

The scripts that made this version, as plain text.

• compose.py254 linesthe nine mosaics: every cut, loop and freeze
• sampler.py154 linesloop, stretch, reverb, echo, freeze, tape stop
• mix.py85 linesthe 178-second set
• sound_design.py91 linesneedle drop, inhales, risers, sub, tape bus
• engines.py367 linesthe ten picture techniques
• vis_common.py106 linesshared embers, archive frames, the finish
• render.py41 linesrenders frames and encodes
• analyze.py21 linestempo and onsets of each source track