Chord Detector

The audio is split into short segments; for each segment a chroma (pitch-class) profile is extracted and matched against templates for major, minor, 7th, diminished, augmented, and suspended chords using cosine similarity. The best match above the confidence threshold becomes the chord for that moment.

Segments below the confidence threshold (~0.6) are dropped, so quiet, percussive, or ambiguous passages may show gaps. Dense mixes, heavy distortion, and inversions can also fool a template match. It works best on clear harmonic material like piano, guitar, or pad-driven tracks.

It is inferred from the detected chord roots - each major and minor scale is scored by how many chord roots fall inside it, with extra weight on the tonic and dominant. It is a best guess, not a definitive analysis.

Default is 0.5 seconds. Smaller segments catch fast chord changes but are noisier; larger segments are steadier but blur quick changes. Adjust it before uploading.

Clear piano, guitar, vocal, or pad-led harmony gives the strongest result. Dense mixes, distortion, drums, and very quick changes need extra listening checks.

Short analysis windows can react to melody notes, bass movement, drums, or passing harmony. Treat rapid low-confidence changes as candidates, listen around the timestamp, and combine them into a simpler progression when the recording supports it.