Chain of Thoughts prompt

METER: 3/4

TITLE
Bar 1 — Register-partitioned, non-isomorphic scale; airy monophony with internal crescendo.

INSTRUMENTS (EXACT)
Use these six instruments and no others:
[alto_flute, bass_clarinet, trumpet, violin, cello, double_bass].
Every instrument must appear in this bar (one monophonic line each; no chords).

GOAL (MUSICAL TECHNIQUE TO APPLY)
Compose the bar by first designing a register-partitioned, non-isomorphic scale and then realizing it *through the PTs* (pitch/time/duration/velocity). Do not output the scale as data; instead, embed its effect in your pitch transformations + seeds.

1) REGISTER PARTITION (per instrument)
   • Split each instrument’s hard MIDI range into three contiguous bands: LOW / MID / HIGH (bottom/middle/top third of its range).
   • For the *piece as a whole*, assign three disjoint pitch-class sets (pcs) — one set per band — so that:
       – LOW_pcs, MID_pcs, HIGH_pcs are pairwise disjoint,
       – their union is all 12 pcs (0..11),
       – each band has exactly 4 pcs,
       – internal adjacency within each band suggests thirdal/quartal neighborhoods (prefer step relations ≈ ±3 or ±4 semitones); avoid trivial uniform cycles.
   • Non-isomorphism: the playable pcs change when a note crosses a band boundary. (The same pitch letter in a higher register is *not* guaranteed the same pc availability as below.)

2) MELODIC REALIZATION (how to use PTs to stay inside the band pcs)
   • PITCH dimension: use only add/sub integers to construct a short degree-step pattern relative to the ordered pcs of the current band at each onset.
       – Choose a repeating pattern using small steps (±1, ±2 degrees within the band’s ordered pcs) with occasional leaps (±5, ±7, ±12 semitones) immediately followed by corrective stepwise motion that lands back on a band-legal pc.
       – If a planned semitone add/sub would land off the band set, apply a one-time ±1 adjustment at that step so the resulting MIDI pitch snaps to the nearest legal pc for the band before continuing the planned pattern.
       – Avoid >3 same-direction moves in a row; net drift per line per bar in [−2..+2].
       – Choose the pitch seed near each instrument’s tessitura center so that the opening note is already a band-legal pc.
   • TIME dimension: strictly increasing onsets using only add {1,2,3,4}; no zeros; no mul/div; no chords.
   • DURATION dimension: values in {1,2,3,4} and MAX(duration) ≤ s_min where s_min is that instrument’s smallest time step, ensuring monophony and no overlaps.
   • VELOCITY dimension: smooth crescendo across the bar ≈ 50 → 80, with per-step deltas ≤ 8. (Shape may be slightly asymmetrical but must rise overall.)

3) TEXTURE, DENSITY, ROLES (match the original Bar-1 character)
   • Airy, interleaved entries; avoid vertical stacking: ≤ ~1/3 of onsets may coincide across instruments.
   • Target onsets per instrument (soft bounds; stay close):
       – alto_flute:      6–10 (MID↔HIGH bands)
       – violin:          5–9  (MID↔HIGH)
       – bass_clarinet:   3–6  (LOW↔MID)
       – trumpet:         2–5  (MID↔HIGH), sparser color
       – cello:           2–5  (LOW↔MID)
       – double_bass:     2–4  (LOW), foundational, the sparsest
   • Keep every realized MIDI pitch inside the instrument’s hard range and inside the band-legal pcs at its onset register.
   • Vertical color at chance alignments favors interval-classes {1,2,5,6}; avoid triadic pull and consecutive perfect-fifth alignments; no functional cadences.

FORM FOR THIS PROMPT
Compose exactly one bar (12 ticks at 1/16 grid). All notes must end ≤ tick 12. Realize the above purely through your PT design (transformations + seeds). Return a single bundle with exactly six features (one per listed instrument) and a run_plan that produces the lines as specified.