Module key_detect 

Musical key detection via chromagram analysis.

Computes a 12-bin chroma vector (C, C#, D, …, B) from audio PCM data using frequency-domain energy estimation, then correlates against Krumhansl-Kessler key profiles for all 24 major/minor keys.

Constants

MAJOR_PROFILE 🔒

Krumhansl-Kessler major key profile (starting from C).

MINOR_PROFILE 🔒

Krumhansl-Kessler minor key profile (starting from C minor).

NOTE_NAMES 🔒

Note names for display.

Functions

compute_chromagram 🔒

Compute a 12-bin chromagram from PCM audio.

detect_key

Detect the musical key of an audio file. Returns a string like “C Major”, “F# Minor”, or None if detection fails.

goertzel 🔒

Goertzel algorithm: compute energy at a specific frequency. Much more efficient than FFT when you need only a few frequency bins.

match_key_profile 🔒

Match a chroma vector against all 24 key profiles (12 major + 12 minor). Returns the best-matching key name.

profile_correlation 🔒

Pearson correlation between chroma and a rotated key profile.