write-afrobeat-album

name	write-afrobeat-album
description	Generate Afrobeat / Afropop tracks (Fela-style dom7 vamps, layered percussion, ostinato guitar, horn stabs). Uses CoupledHMMHarmonizer with funk profile (dom7+min7) for the dom7 vamps + chord-tone contour, and manual MixingDesk/MasteringDesk. AfrobeatsGenerator, AfroPercussionGenerator, Arpeggiator (ostinato), BrassSection, WalkingBass, PianoComp.

Write Afrobeat Album

Use this skill for Afrobeat (Fela Kuti — extended dom7 vamps, layered percussion, horn riffs) and Afropop (Burna Boy / Wizkid — more produced). Uses CoupledHMMHarmonizer + funk profile + chord-tone contour + manual MixingDesk/MasteringDesk, with the dedicated AfrobeatsGenerator / AfroPercussionGenerator.

1. Why funk profile

Afrobeat is dom7-vamp based (F7 – Bb7 – C7, bluesy I7–IV7–V7). The funk profile (completion_bonus={8:5.0, 7:4.0}, dom7+min7) retains the dom7s spelt in the contour — exactly the same mechanism as minor blues. The dom7s are chromatic to a major key (F7's ♭7 Eb ∉ F major), but the contour forces them despite key_coupling. (chord-type codes: 7=min7, 8=dom7.)

2. Chord-tone contour — dom7 vamp

KEY = Scale(root=5, mode=Mode.MAJOR)            # F major (afrobeat classic); dom7s are chromatic, forced by contour
FORM = ["I7","IV7","I7","V7"]                   # 4-bar vamp, repeat
ARP  = {"I7":[5,9,0,3], "IV7":[10,2,5,8], "V7":[0,4,7,10]}  # F7 / Bb7 / C7
# config=harmonizer_profile("funk")
# contour builder identical to write-blues-album §2; base must be a multiple of 12

Expected output: 5:7 10:7 5:7 0:7 = F7–Bb7–F7–C7, 48/48 dom7 retained.

3. Required imports + pipeline

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(67)

from melodica.harmonize.coupled_hmm import CoupledHMMHarmonizer
from melodica.harmonize import harmonizer_profile
from melodica.generators import GeneratorParams
from melodica.generators.afrobeats import AfrobeatsGenerator
from melodica.generators.afro_percussion import AfroPercussionGenerator
from melodica.generators.walking_bass import WalkingBassGenerator
from melodica.generators.piano_comp import PianoCompGenerator
from melodica.generators.arpeggiator import ArpeggiatorGenerator
from melodica.generators.brass_section import BrassSectionGenerator
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=-15.0):
    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

DRUMS=0 (percussion → channel 10), ELEC_BASS=33, EPIANO=4 (Rhodes), CLEAN_GUITAR=27, BRASS=62 (brass section), NYLON_GUITAR=24, SAX=66.

5. Generators (verified kwargs)

groove = AfrobeatsGenerator(
    GeneratorParams(density=0.50),
    variant="afrobeats", log_drum_density=0.60, shaker_pattern="sixteenth",
    include_piano=False, bounce_amount=0.60, percussion_layer=True,
).render(chords, key, dur)                        # full afrobeats groove (log drums + shaker + percussion)
perc = AfroPercussionGenerator(
    GeneratorParams(density=0.50),
    ensemble="west_african", include_pitched=False, call_response=True, swing=0.55,
).render(chords, key, dur)                        # extra west-african percussion layer
bass = WalkingBassGenerator(
    GeneratorParams(density=0.60, key_range_low=28, key_range_high=43),
    approach_style="mixed", add_chromatic_passing=True, swing_eighth_ratio=0.56,
).render(chords, key, dur)                        # repetitive pocket bass
keys = PianoCompGenerator(
    GeneratorParams(density=0.30, key_range_low=48, key_range_high=72),
    comp_style="pop", voicing_type="close", accent_pattern="syncopated", chord_density=0.55,
).render(chords, key, dur)
guitar = ArpeggiatorGenerator(
    GeneratorParams(density=0.55, key_range_low=50, key_range_high=67),
    pattern="up", note_duration=0.5, octaves=1,
).render(chords, key, dur)                        # the classic 2-chord guitar ostinato
horns = BrassSectionGenerator(
    GeneratorParams(density=0.14, key_range_low=54, key_range_high=72),
    articulation="hit", voicing="closed", intensity=0.70, divisi_count=3,
).render(chords, key, dur)                        # horn stabs / riffs

Layering — afrobeat lives on layered percussion. Use AfrobeatsGenerator (set include_piano=False so it stays pure percussion on the drum channel) plus AfroPercussionGenerator for the second percussion layer, then bass/keys/guitar/horns on top. Both percussion generators → GM program 0.

6. Subgenres

Subgenre	Key	BPM	Profile	Vamp	LUFS	Example
Afrobeat (Fela)	F major	108	funk	I7-IV7-I7-V7 (dom7)	-15	scripts/albums/afro/afrobeat.py
Afropop (modern)	Ab / Db major	102–112	funk or pop	shorter vamps, brighter	-14	—
Afro-house	A minor	120	lofi	diatonic 7th loop	-14	(see afro_house.py generator)

7. Pitfalls

Issue	Fix
Dom7 vamp came out as triads	Use funk profile (not pop). Spell the dom7 tones in the contour ({8:5} only fires when present).
Pitched notes on the drum track	Set AfrobeatsGenerator(include_piano=False) and AfroPercussionGenerator(include_pitched=False) so percussion stays on channel 10.
Too much percussion clutter	Two percussion generators is intentional (layered), but lower density / log_drum_density if it overpowers the bass/horns.
Horns inaudible	BrassSectionGenerator at low density (~0.14) for stabs; raise intensity.
Track transposed	Contour base must be a multiple of 12.
MasteringDesk crash	Returns tuple (mastered, cc) — unpack.
Stale kwargs from other skill docs	The kwargs above are verified. Other docs' voicing_style/style="walking" raise ValueError — use voicing_type/approach_style.