LOOP_CADENCE.md

music/complete_tracks/LOOP_CADENCE.md

THE LOOP-SEAM CADENCE, MEASURED

CANON SUBORDINATION — this document is PROPOSAL-TIER: it serves canon and never outranks it.

The canon: the CVD · the T1 foundation docs · the T0 registries (registries/) · the spine

(docs/spine/CH_*.md) · the region pages (_source/02_Tier_2_Region_Pages/). Authority order: docs/DOC_MAP.md § 0.

Canon served: T0_Theme_Registry.

If this document disagrees with canon, CANON WINS and this document is the defect.

Emitted by harness/music_gen/loop_cadence.py, read off the shipped MIDI.

0. What this replaces

All twenty generation records carried a loop_seam.cadence field and all twenty carried the

SAME SENTENCE — the card's specification, copied onto the artifact unchanged, whatever the

notes at the loop point did. A specification restated as a result cannot fail, so it cannot

be evidence. These are the notes.

1. The classifier's proofs

constructed cadence	expected	measured	pass	what it proves
`perfect_authentic`	PAC	PAC	PASS	the cadence PHRASE-05 forbids at a loop point is detected and refused
`imperfect_authentic`	IAC	IAC	PASS	a weakened authentic cadence is NOT reported as a perfect one
`half_cadence`	HALF	HALF	PASS	PHRASE-05's first remedy reads as itself
`bvii_substitution`	BVII	BVII	PASS	PHRASE-05's second remedy reads as itself
`plagal`	PLAGAL	PLAGAL	PASS	a plagal close is not an authentic one and is not refused
`open_drone`	OPEN	OPEN	PASS	a drone frame is reported OPEN rather than forced into a triad
`injected_pac_end_to_end`	PAC	PAC	PASS	THE WHOLE PATH, not just the classifier: bar arithmetic, percussion exclusion and the card's tonic all have to be right for a real track's loop point to read PAC when a PAC is put there

2. The twenty loop points

track	arm	key	loop class	penult	final	bass	soprano	class	conf	verdict
HF_MT_01_TITLE	A	D major	none_linear	VII minor	I major	bVII	VI	IAC	medium	GREEN
HF_MT_02_EXPLORATION_TRAVERSAL	B	G mixolydian	phrase_pool	bVII major	bVII major	bVII	IV	BVII	high	GREEN
HF_MT_03_BATTLE_ORDINARY	A	E dorian	short_loop_composed_seam	bVII sus2	VI dim	VI	IV	OPEN	high	GREEN
HF_MT_04_BOSS_CHAPTER	B	C phrygian	short_loop_composed_seam	I minor	I minor	I	V	IAC	high	GREEN
HF_MT_05_BOSS_APEX	A	D minor	multiphase_linear_with_loop_tails	IV power	I power	V	I	OPEN	medium	GREEN
HF_MT_06_SANCTUARY_REST	B	F major	long_loop	V sus2	V major	II	VII	HALF	low	GREEN
HF_MT_07_TRADE_AND_FESTIVAL	A	A major	long_loop	VII dim	I power	bVII	VII	OPEN	medium	GREEN
HF_MT_08_SORROW_LOSS	B	D aeolian	none_linear	IV power	IV sus2	IV	V	OPEN	low	GREEN
HF_MT_09_WONDER_DISCOVERY	A	A lydian	tail_loop	III minor	VII power	bV	V	OPEN	medium	GREEN
HF_MT_10_CREDITS	B	D major	none_linear	I major	I major	I	II	IAC	medium	GREEN
HF_MT_11_REGION_FLORES	A	pentatonic centred on G	long_loop	V major	V sus2	bV	II	HALF	medium	GREEN
HF_MT_12_REGION_BALI	B	pelog-derived scale, reference-composed	long_loop	IV sus2	IV minor	bVI	V	OPEN	medium	GREEN
HF_MT_13_REGION_SUMATRA_JAVA	A	D aeolian	long_loop	bVII major	bVII power	VI	bVII	BVII	medium	GREEN
HF_MT_14_REGION_SRI_LANKA	B	G mixolydian	long_loop	IV sus4	I power	V	I	OPEN	low	GREEN
HF_MT_15_REGION_SOUTH_INDIA	A	a raga-derived collection, reference-composed	long_loop	bII sus4	IV dim	bV	V	OPEN	medium	GREEN
HF_MT_16_REGION_SWAHILI_COAST	B	C dorian	long_loop	II aug	I sus2	I	II	IAC	low	GREEN
HF_MT_17_REGION_ETHIOPIA	A	a four-mode system, reference-composed	long_loop	I sus2	I sus2	I	II	IAC	low	GREEN
HF_MT_18_REGION_CENTRAL_AFRICA	B	F major	long_loop	I major	IV power	IV	III	OPEN	low	GREEN
HF_MT_19_REGION_WEST_AFRICA	A	E minor	long_loop	bVI major	VI quartal	VI	V	OPEN	medium	GREEN
HF_MT_20_REGION_SOUTH_AFRICA	B	A minor	long_loop	bIII power	V power	V	bVI	HALF	low	GREEN

0 of 20 measure a perfect authentic cadence at the loop point.

3. Why each class is or is not allowed

PAC — refused. V to I, root position, tonic in the soprano: the ear is told the piece

is over, and then it starts again. That is the fatigue PHRASE-05 names.

HALF and BVII — the law's own two remedies. Both leave the ear expecting more.
IAC — allowed. The cadence lands on the tonic but the closure is weakened by inversion

or by a soprano that is not the tonic, so the restart does not read as a restart.

PLAGAL — allowed. No leading tone, therefore no closure pressure.
OPEN — allowed. A drone or quartal frame has nothing to close; the cards that end this

way say so in their own prose ("the drone never resolved so nothing closes").

4. How much each reading is worth

conf is high when three or more pitch classes sound at the loop point and the chord

template fits cleanly, medium when three or more sound but the fit is loose, and low

when only two sound — the end of a decaying tail, where naming a root is a guess with a name

on it. A low-confidence reading cannot conceal a PAC: a perfect authentic cadence needs V to

I with the root in the bass and the tonic in the soprano, which cannot be read from fewer

than three classes at all.

Low-confidence loop points: HF_MT_06_SANCTUARY_REST, HF_MT_08_SORROW_LOSS, HF_MT_14_REGION_SRI_LANKA, HF_MT_16_REGION_SWAHILI_COAST, HF_MT_17_REGION_ETHIOPIA, HF_MT_18_REGION_CENTRAL_AFRICA, HF_MT_20_REGION_SOUTH_AFRICA.

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