How accurate is FlexChords?
On full-length songs the model has never trained on, FlexChords identifies 90.2% of chords correctly (root and major/minor), 81.3% including 7th chords, and the root note 92.7% of the time. 88.4% of chord changes land within 0.25 seconds.
Scores are MIREX-style weighted chord symbol recall computed with the open-source mir_eval library: the share of each song's running time where the predicted chord matches a musician-made reference chart. Model FlexCRNN v3, measured 16 October 2026.