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d09f52e | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 | """Tests for the probabilistic functional-harmony grammar.
The grammar must produce musically-shaped phrases: start on tonic, end on a
recognised cadence, and (crucially) every chord must survive the gold gate when
rendered in a key. It must be deterministic under a seed and genuinely diverse.
"""
from music21 import key
from harmony_dataset.grammar import generate_phrases
from harmony_dataset.cadence import classify_cadence
from harmony_dataset.verify import verify_chord
from harmony_dataset.vocabulary import Analysis, chord_symbol_from_figure
class TestParseSpec:
def test_specs_round_trip_to_labels(self):
assert Analysis.parse("ii7").dcml_label() == "ii7"
assert Analysis.parse("IM7").dcml_label() == "IM7"
assert Analysis.parse("iio6").dcml_label() == "iio6"
assert Analysis.parse("ii%65").dcml_label() == "ii%65"
assert Analysis.parse("V7/V").dcml_label() == "V7/V"
assert Analysis.parse("viio7").dcml_label() == "viio7"
class TestPhraseShape:
def test_starts_on_tonic(self):
for mode in ("major", "minor"):
for phrase in generate_phrases(mode, 40, seed=1):
assert phrase[0].numeral in {"I", "i"}
assert phrase[0].relativeroot is None
def test_ends_on_cadence(self):
for mode in ("major", "minor"):
for phrase in generate_phrases(mode, 40, seed=2):
assert classify_cadence(phrase) is not None
def test_reasonable_length(self):
for phrase in generate_phrases("major", 40, seed=3):
assert 2 <= len(phrase) <= 9
class TestGoldGateCompatibility:
def test_every_chord_verifies_in_reference_key(self):
# nothing the grammar emits should fail the dual-derivation check
for mode, k in (("major", "C"), ("minor", "a")):
K = key.Key(k)
for phrase in generate_phrases(mode, 60, seed=4):
for a in phrase:
sym = chord_symbol_from_figure(a.music21_figure(), K)
assert verify_chord(a, sym, K).ok, f"{a.dcml_label()} -> {sym} in {k}"
class TestDeterminismAndDiversity:
def test_deterministic(self):
a = [tuple(p.dcml_label() for p in ph) for ph in generate_phrases("major", 30, seed=7)]
b = [tuple(p.dcml_label() for p in ph) for ph in generate_phrases("major", 30, seed=7)]
assert a == b
def test_distinct_shapes(self):
shapes = {tuple(p.dcml_label() for p in ph) for ph in generate_phrases("major", 120, seed=9)}
# the grammar should yield real variety, not a handful of templates
assert len(shapes) >= 40
def test_uses_secondary_dominants(self):
seen = set()
for mode in ("major", "minor"):
for ph in generate_phrases(mode, 150, seed=11):
for a in ph:
if a.relativeroot is not None:
seen.add(a.dcml_label())
assert seen, "grammar never produced a secondary dominant"
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