The club cousin of the flutterbap family (pop/marimba/). Where flutterbap skips through the park, imab goes out at night: a four-on-the-floor dance record sung around one hook — i'm a butterfly — with the "i-MAB" stamp as its chant.

Built bottom-up from AC instruments (marimba modal synth, perc synth, the clubber360 floor recipes) — never generated wholesale. Vocals ship aesthetivoxed, never raw.

musicality (locked unless we relock it) #

BPM 124 — the flutterbap family tempo; beat ≈ 0.4839 s, bar ≈ 1.9355 s.
Key: A minor verses / C major hook (relative pair). The hook quotes flutterbap's opening cell (E5 G5 C6) exactly.
Hook progression: Am | Am | G | G | C | C | F | G (8-bar loop). Bass roots A2 A2 G2 G2 C3 C3 F2 G2.

the hook, syllable by syllable (CAPS = held) #

One line per bar; beats in parentheses. Score doc: imab.np.

1  i'm(E5 @1)  a(G5 @1.5)  BUT(C6 @2, 1.5 beats)  ter(B5 @3.5)  fly(G5 @4)
2  …rest…                              i(A4 @4)  MAB(E5 @4.5)     ← pickup
3  i'm(D5 @1)  a(G5 @1.5)  BUT(B5 @2, 1.5 beats)  ter(A5 @3.5)  fly(G5 @4)
4  …rest…                              i(A4 @4)  MAB(E5 @4.5)
5  i'm(E5 @1)  a(G5 @1.5)  BUT(C6 @2, 1.5 beats)  ter(D6 @3.5)  fly(E6 @4)   ← the lift
6  FLY(E6 @1, 2 beats)  →  (C6 @3, 1.5 beats)
7  no(E6 @1) thing(D6 @1.5) holds(C6 @2) me(G5 @2.5) DOWN(A5 @3, 1.5 beats)
8  i(A4 @1) MAB(E5 @1.5, held)   i(A4 @3) MAB(E5 @3.5, held)     ← the chant

Lineage: bars 1/5 = flutterbap bar 1 (E5 G5 C6); bar 3 = flutterbap bar 3 (D5 G5 B5); bar 7 = "nothing holds me" from lately-when-i-fly (E6 D6 C6 G5).

tools #

node pop/imab/bin/hitbaker.mjs         # the CHART arrangement (single-study calibrated):
                                       #   104-bar verse/pre/chorus form, G-pedal break,
                                       #   terminal-lift finale → out/imab-hitbaker-demo1
                                       #   vocal doors: choruses at bars 24 / 56 / 76 (A = 24)
node pop/imab/bin/fetch-real-kit.mjs   # CC0 Freesound drum one-shots → samples/real/
                                       #   (hitbaker prefers these; provenance in
                                       #   kit-real.json + the pop menu sample registry)
node pop/imab/bin/gen-click.mjs        # click + guide → out/ (juke-sync picks mp3s up)
node pop/imab/bin/gen-kit.mjs          # one-shot sample kit → samples/kit/
node pop/imab/bin/lyrictrack.mjs       # canonical lyric timing: drawn boundaries →
                                       #   stem + floor JSONs + grid-fit proof mp4
pop/.venv/bin/python pop/imab/bin/lyricscroll.py
                                       # the scrolling review clip: alignment-video
                                       #   chassis over the real floor mix, lyric
                                       #   ribbon underneath (needs lyrictrack first)
pop/.venv/bin/python pop/imab/bin/melodyproof.py [take…]
                                       # DOES HE SING WHAT WE WROTE? every syllable's
                                       #   sung pitch vs melody.json, per take, two
                                       #   stages: SET (vocalset's note-locked render —
                                       #   proves the render) and RAW (the demucs stem —
                                       #   the verdict). Register fitted per take in
                                       #   cents; boundaries from drawn / dtw / notealign.
                                       #   → out/melodyproof.html (?only=<take-suffix>)
                                       #   also writes boundaries-dtw-<take>.json (the
                                       #   lead's hand warped onto each take) for the wizard
node pop/imab/bin/syllawizard.mjs <take> # draw syllable rectangles on THIS take's
                                       #   spectrogram (takes/<take>/ in the cache; seeds
                                       #   from processed → drawn → dtw boundaries)
pop/.venv/bin/python pop/imab/bin/notealign.py <wav> <notes.json>
                                       # forced alignment: the written melody DTW'd onto
                                       #   the f0 track → syllable spans (a proposal)
node pop/imab/bin/setalign.mjs         # every set retimed onto the lead's syllable
                                       #   onsets → out/imab-set-<take>-aligned.wav +
                                       #   imab-sets-successive.mp3 (no layering)
open pop/imab/review.html              # scroll-through of every demo, take and spine

boundary files — which timebase #

processed-boundaries-<take>.json — @jeffrey's hand on the SET (vocalset's stretched, note-locked wav; the wizard's takes/<take>/spec.png). Feeds vocalset.
boundaries-drawn-<take>.json — @jeffrey's hand on the RAW stem. The lead's (Sep 1) carries the a/but mislabel that lyric-overrides.json drawnFix corrects; 7427's (Sep 9, drawn on neo) is clean.
boundaries-dtw-<take>.json — melodyproof's warp of the lead's SET hand onto another take's SET, by MFCC+RMS DTW. A seed, not a truth.
melody.json — the notepat ground truth, one note per syllable. Edit here, not in the scripts.

where the work lives #

The raw takes (toolchain/whistlegraph/downloads/whistlegraph-<take>.wav), their demucs stems and the full ~/.cache/ac/imab work dir live on neo; blueberry holds copies of the six stems + wavs as of 2026-09-13. Uncommitted lane work has stranded on both machines before — git status pop/imab on each before assuming a fix "already happened".

out/imab-click-124 — 2-bar count-in, then 64 bars. Beat 1 accented, brighter door tick at every 8-bar phrase start.
out/imab-guide-124 — the same click with the hook melody (xylophone) and bass roots looping, for practicing and cutting takes.

recording performances #

Record at 48 kHz against the click or guide (one ear).
Drop files in performances/ named imab-take-NN-<desc>.wav.
Log every take in performances/manifest.json immediately — a take that isn't logged doesn't exist. Fields: { id, file, date, kind (vocal|whistle|clap|beatbox|other), content, clickUsed, keeper, notes }.
Raw takes never ship: vocal comps go through the aesthetivox chain (pop/bin/autotune.py, A minor) before they touch a mix.

aesthetivox-alignment-video #

bin/aesthetivox-alignment-video.py — the named feature: a piano-roll study mp4 (syllable blocks at sung pitch with their own waveform envelopes printed inside, numbered bars, per-beat tinted grid, kick floor, scrolling waveform, fixed playhead) over the click+kick+vocal study audio. The alignment scrutiny instrument for every aesthetivox vocal. Display latency is calibrated with loner's synccal.mp4; set SYNC_MS to the value that locks.

samples #

samples/kit/ — sample-free one-shots rendered from the AC engines (perc kit, bass-perc, xylophone hook notes, click ticks), manifest in kit.json. Chops of logged performances go in samples/perf/ with their own manifest, named after the take they came from.

the dance track (build plan) #

Carrying the loner/clubber360 learnings:

everything on ONE grid; stretches only at exact 0.5×/0.25× ratios
rhythmic narrative as a palindrome — the floor assembles act by act, reduces to a seed in the kickless break, returns whole at the drop, peels in reverse; kick turn-figures before doors; click-rush doors
sidechain pump on melodic layers keyed to the kick; phrase rests (last half-bar of each 8-bar phrase floors the decorative layers — kick, bass and the voice are never gated)
vocal-keyed wub swelling only in the gaps the voice leaves
master: cut-wax material chain posture; MEASURE → one static dB → true-peak limit; −11.5 juke print, −13.5 release
build pipeline lives in bin/ in the repo, work dir in ~/.cache/ac/imab — never in a scratchpad