nullabye #

A lullaby with no instruments in it — every sound is carved out of cancelled pink noise with EQ automation. Part of the pixsies body.

The technique #

Study after Andy Brewer's "this song has no instruments in it":

1. Duplicate a pink-noise track and invert the phase of the copy. Summed, they null to perfect silence.
2. Put an EQ on the copy. Anywhere the EQ deviates from flat, the cancellation breaks — what you hear is the difference signal.
3. A narrow peaking bell at a note frequency therefore becomes a breathy pitched voice pulled out of the hiss. Automate 24 bells and you have a 24-voice "noise-sine" polysynth.

Two properties make this more than a parlor trick:

• Pink noise + constant-Q bells = equal voice energy at any pitch (pink is equal energy per octave; a constant-Q band covers a constant fraction of an octave). Bass notes and whistle notes come out at the same loudness for free.
• High-Q bells ring (ring time ≈ Q/πf), so the filters supply natural attack/release tails without any amplitude envelope on the audio path — the "instrument" has built-in articulation.

We honor the original's constraint: the renderer allocates from a pool of at most 24 EQ points and throws if the score ever wants a 25th. nullabye uses 15, peaking at 10 sounding simultaneously.

Run #

node pop/nullabye/bin/render-nullabye.mjs            # → out/nullabye.mp3
node pop/nullabye/bin/render-nullabye.mjs --proof    # flat EQ ⇒ bit-exact silence

--proof renders with every band forced flat and asserts the output is bit-exact digital zero — the cancellation is real, not just quiet.

nuellaby — the complexity-arch cut #

Second cut in the lane (bin/render-nuellaby.mjs → out/nuellaby.mp3, exactly 2:00 — 38 bars at 76 BPM is 120.0 s on the nose): the EQ rack doubles 2 → 4 → 8 → 16 → 32 → 64 → 128, then folds back down 64 → 32 → 16 → 8 → 4 → 2 and empties — band count as the musical-complexity arc itself. Up in 4-bar chord cycles (2 bars for the sparse openers), down in quick 2-bar halvings (arch form; the ×128 bloom is the keystone, with a 12-partial harmonic choir + 21-band diatonic halo).

The spectrum is carved into zones, each owned by its own layers: sub (pitch-dropping 110→42 Hz kick, bass roots) · bass (drones, tom fills, floor pad) · low-mid (chord pads, detuned doubles) · mid (lead whistle, harmony, choir) · upper-mid (octave lead, arps, snare-shh) · presence (sparkles, rim clicks, risers) · air (closed/open hats, shaker 16ths, ticks, veils).

New engine idea: lanes — persistent monophonic EQ points that consecutive notes reuse (the bell drags to a new frequency, clipping the old ring), so each stage's band count is the honest number of points on the rack. A per-stage cap audit throws if any stage exceeds its power of two; measured arch: 2/2 4/4 8/8 16/16 30/32 51/64 92/128 49 29 15 8 4 2. --proof works here too (92 lanes flat ⇒ bit-exact silence).

The song (nullabye) #

76 BPM, 4/4, C major, 24 bars (≈ 1:19). Chord cycle C / Am9 / Fmaj9 / Gadd9.

• breaths (bars 0–3) — wide low-Q bells swell in and out of the null so the trick is audible before the song starts.
• lullaby-a (4–11) — Q 28 chord pads, Q 55 whistle lead (±0.12% L/R detune), heartbeat kick (Q 4.5 bell at 54 Hz) from bar 8.
• lullaby-b (12–19) — adds half-note bass roots, 8.2 kHz hat ticks, Q 70 high sparkles on offbeats.
• veil-lifts (20–23) — one wide bell sweeps 250 Hz → 6 kHz letting the raw noise wash through, a last lone whistle, then the EQ goes flat and the song ends in literal silence.

nullabata — the sonata cut #

Third cut in the lane (bin/render-nullabata.mjs → out/nullabata.mp3, ~4:21): nullaby + sonata. Four movements run attacca — no silence between them — bound by one lullaby motif (semitone offsets from a per-movement voice tonic) transformed in each:

I.   Andante   C maj    72 BPM   18 bars   the theme, lyrical whistle + warm pads
II.  Scherzo   A min   132 BPM   32 bars   theme shattered into a fast arp/twinkle cloud
III. Adagio    F maj    56 BPM   13 bars   theme sung slow over sustained pads + drones
IV.  Finale    C maj    84 BPM   30 bars   theme recapitulated: 2→bloom→2 accumulation

Clarity is a Q decision. In this engine every voice is a peaking-EQ bell on noise: a narrow (high-Q) bell rings like a breathy tone, a wide (low-Q) bell passes a wide band of raw noise (hiss). nullabata runs the engine at its tonal extreme — high Q on every pitched voice (lead 110, pads 55, drones 45, choir/halo 50+), no wide "veil" wash (the single biggest static source in the lane), and percussion kept narrow (no shaker / open-hat; hats are narrow pitched ticks). Master drops the treble boost and adds a 15 kHz lowpass; energy above 12 kHz sits 36 dB below the full band.

Otherwise reuses the engine wholesale — lanes, the serial-dB disjoint-frequency discipline, sorted mono events. The loudness ride is per-second, movement-aware (each movement targets its own dBFS curve) so the four very different tempos and densities land evenly; integrated −19.1 LUFS. The Finale runs a compact accumulation arch (47-point roster, 2 → bloom → 2). --proof passes with all 47 lanes flat (bit-exact silence); the --bake → c/run-c.mjs C path renders the same score.

node pop/nullabye/bin/render-nullabata.mjs            # → out/nullabata.mp3
node pop/nullabye/bin/render-nullabata.mjs --proof    # flat ⇒ bit-exact silence
node pop/nullabye/bin/render-nullabata.mjs --bake out/nullabata.score.txt