Files
pytheory/examples/key_explorer.py
T
kennethreitz 9da3ac8b28 Add 12 example scripts showcasing pytheory features
- circle_of_fifths.py — visualize keys around the circle
- chord_identifier.py — identify chords from notes and fingerings
- key_explorer.py — explore keys, signatures, progressions, borrowed chords
- temperament_comparison.py — compare equal, Pythagorean, and meantone
- chord_tension.py — analyze tension, consonance, and voice leading
- world_scales.py — scales from 6 musical traditions
- fretboard_explorer.py — instruments, tunings, capo transposition
- midi_converter.py — MIDI ↔ note ↔ frequency reference
- progression_writer.py — famous progressions, Nashville numbers, random generation
- interval_trainer.py — interval names, songs, and consonance ranking
- overtone_series.py — harmonics and why chords sound good
- key_detection.py — detect keys from melodies and chord progressions

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-22 20:27:18 -04:00

59 lines
1.7 KiB
Python

"""Explore a key — its chords, progressions, and relationships."""
from pytheory import Key
def explore_key(tonic, mode="major"):
key = Key(tonic, mode)
sig = key.signature
acc = ", ".join(sig["accidentals"]) or "none"
print(f"{'=' * 60}")
print(f" {key}")
print(f"{'=' * 60}")
print()
print(f" Scale: {' '.join(key.note_names)}")
print(f" Signature: {sig['sharps']} sharps, {sig['flats']} flats ({acc})")
print(f" Relative: {key.relative}")
print(f" Parallel: {key.parallel}")
print()
# Diatonic triads
print(" Diatonic Triads:")
for chord in key.scale.harmonize():
numeral = chord.analyze(tonic, mode) or "?"
print(f" {numeral:6s} {chord.identify()}")
print()
# Seventh chords
print(" Seventh Chords:")
for name in key.seventh_chords:
print(f" {name}")
print()
# Common progressions
print(" Common Progressions:")
progressions = {
"Pop": ("I", "V", "vi", "IV"),
"Blues": ("I", "IV", "V"),
"50s": ("I", "vi", "IV", "V"),
"Jazz": ("ii", "V", "I"),
}
for label, numerals in progressions.items():
chords = key.progression(*numerals)
names = [c.identify() for c in chords]
print(f" {label:8s} {''.join(numerals):20s} {''.join(names)}")
print()
# Borrowed chords
borrowed = key.borrowed_chords
if borrowed:
print(f" Borrowed from {key.parallel}:")
for chord in borrowed[:4]:
print(f" {chord.identify()}")
print()
# Explore several keys
for tonic, mode in [("C", "major"), ("G", "major"), ("A", "minor"), ("E", "major")]:
explore_key(tonic, mode)