write-rnb-album

# Write R&B Album Use this skill for **slow-jam / quiet-storm R&B** (D'Angelo, Sade, early Erykah) and **Pop R&B** (modern radio R&B). Uses **CoupledHMMHarmonizer** + **chord-tone-contour harmony** + **manual MixingDesk/MasteringDesk**. ## 1. Two flavors, two profiles | Flavor | Harmony | Profile | `completion_bonus` | Key | |---|---|---|---|---| | **Slow jam** | lush m7 / dom7 / 9ths | `neo_soul` | `5.0` uniform + low coupling + `extended_chord_penalty=0.0` (lush 9ths) | Dorian (e.g. Eb) | | **Pop R&B** | clean triads, catchy | `pop` | `0.0` (no 7th retention — pure triads) | Major (e.g. Ab) | - `neo_soul` rewards **all** 7th types uniformly and lets extensions (9ths) color the voicings — the warm, jazzy R&B sound. - `pop` gives **clean triads only**; spelled 7ths collapse to triads. Correct for bright pop-R&B, wrong if you want 7th color. - Don't confuse this with the older `write-rnb-soul-album` skill, which uses a different pipeline (`HMM3Harmonizer` + `produce_track`); this skill uses the proven `CoupledHMMHarmonizer` + manual mix. ## 2. Chord-tone contour technique Spell each bar's target chord as its chord-tone arpeggio so the profile retains the exact quality. **Slow jam** (Eb Dorian i–iv–i–V7 loop, m7+dom7): ```python KEY = Scale(root=3, mode=Mode.DORIAN) # Eb Dorian FORM = ["Im7","IVm7","Im7","V7"] ARP = {"Im7":[3,6,10,1], "IVm7":[8,11,3,6], "V7":[10,2,5,8]} # Ebm7 / Abm7 / Bb7 # config=harmonizer_profile("neo_soul") ``` **Pop R&B** (Ab major I–V–vi–IV axis, triads): ```python KEY = Scale(root=8, mode=Mode.MAJOR) # Ab major FORM = ["I","V","vi","IV"] ARP = {"I":[8,0,3], "V":[3,7,10], "vi":[5,8,0], "IV":[1,5,8]} # Ab / Eb / Fm / Db # config=harmonizer_profile("pop") ``` See §2 of `write-blues-album` for the full `make_chords()` contour builder (identical pattern; contour base must be a multiple of 12). ## 3. Required imports + pipeline ```python import random, sys, warnings from pathlib import Path REPO = Path(__file__).resolve().parents[3]; sys.path.insert(0, str(REPO)) warnings.filterwarnings("ignore"); random.seed(91) from melodica.harmonize.coupled_hmm import CoupledHMMHarmonizer from melodica.harmonize import harmonizer_profile from melodica.generators import GeneratorParams from melodica.generators.walking_bass import WalkingBassGenerator from melodica.generators.piano_comp import PianoCompGenerator from melodica.generators.blues_lick import BluesLickGenerator from melodica.generators.solo_melody import SoloMelodyGenerator from melodica.generators.ambient import AmbientPadGenerator from melodica.generators.drum_kit_pattern import DrumKitPatternGenerator from melodica.generators.ghost_notes import GhostNotesGenerator from melodica.shorts_mixing import MixingDesk from melodica.shorts_mastering import MasteringDesk from melodica.midi import export_multitrack_midi def _mix(raw, bpm, gains, lufs=-16.0): desk = MixingDesk(niche_cfg={}); desk.track_gains.update(gains) mixed = desk.apply_mixing(raw, [], int(bpm)) mastered, _cc = MasteringDesk(target_lufs=lufs).apply_mastering(mixed) # tuple return mastered ``` ## 4. GM programs `EPIANO=4` (Rhodes), `ELEC_BASS=33`, `FRETBASS=35`, `CLEAN_GUITAR=27`, `SYNTH_PAD=88`, `LEAD_SYNTH=85`, `TRUMPET=56`, `DRUMS=0`. ## 5. Generators (verified kwargs) ```python rhodes = PianoCompGenerator( GeneratorParams(density=0.28, key_range_low=48, key_range_high=72), comp_style="jazz", voicing_type="rootless", accent_pattern="syncopated", chord_density=0.50, ).render(chords, key, dur) # comp_style ∈ {jazz, pop, bossa, waltz} bass = WalkingBassGenerator( GeneratorParams(density=0.50, key_range_low=28, key_range_high=40), approach_style="mixed", add_chromatic_passing=True, swing_eighth_ratio=0.56, ).render(chords, key, dur) drums = DrumKitPatternGenerator( GeneratorParams(density=0.07), style="funk", groove_swing=0.56, fill_frequency=0.06, auto_fills=True, ).render(chords, key, dur) # "hiphop" for modern pop-R&B backbeat ghosts = GhostNotesGenerator( GeneratorParams(density=0.03), target="snare", pattern="jazz", ghost_velocity=26, ghost_density=0.35, ).render(chords, key, dur) guitar = BluesLickGenerator( GeneratorParams(density=0.18, key_range_low=50, key_range_high=70), lick_style="standard", rest_probability=0.60, bend_probability=0.12, ).render(chords, key, dur) # sparse guitar fills pad = AmbientPadGenerator( GeneratorParams(density=0.10, key_range_low=36, key_range_high=60), voicing="spread", overlap=0.3, ).render(chords, key, dur) # voicing ∈ {open, spread} lead = SoloMelodyGenerator( GeneratorParams(density=0.20, key_range_low=58, key_range_high=79), style="blues_lick", blues_notes=True, chromaticism=0.30, vibrato_depth=0.5, ).render(chords, key, dur) # style default "blues_lick"; smooth R&B lead ``` **Gradual build** — gate a lead to enter after N bars: ```python def _gate(notes, start_at): kept = [n for n in notes if getattr(n, "start", 0.0) >= start_at] return kept if kept else notes lead = _gate(SoloMelodyGenerator(...).render(chords, key, dur), start_at=8 * bars_per_chord) ``` ## 6. Subgenres | Subgenre | Key | BPM | Profile | Loop | LUFS | Example | |---|---|---|---|---|---|---| | Slow jam / quiet storm | Eb Dorian | 74 | `neo_soul` | i-iv-i-V (m7+dom7) | -16 | `scripts/albums/rnb/slow_jam.py` | | Pop R&B | Ab major | 98 | `pop` | I-V-vi-IV (triads) | -14 | `scripts/albums/rnb/pop_rnb.py` | | Bedroom R&B | F minor | 70 | `lofi` | diatonic 7th loop | -18 | — | ## 7. Pitfalls | Issue | Fix | |---|---| | 7ths/9ths collapse to triads in slow jam | Use `neo_soul` (not `pop`). Pop has `completion_bonus=0`. | | Pop R&B sounds too jazzy/busy | Use `pop` profile + triad contour (3 notes/bar), not 7ths. | | Track transposed unexpectedly | Contour base must be a multiple of 12. | | Lead plays continuously, no space | Use `BluesLickGenerator` (has `rest_probability`) for the lead, or gate it; `SoloMelodyGenerator` runs continuous. | | `MasteringDesk` crash | Returns tuple `(mastered, cc)` — unpack. | | Stale kwargs | Use `voicing_type`/`comp_style`/`approach_style` (verified), not the `voicing_style`/`style="walking"` seen in older docs. |