A fixed 0.5 alignment-score cutoff flagged 73-99% of notes on sung
vocals, so the flag pointed nowhere. Scores still separate bad words from
good ones, but their scale differs from song to song: flag a word below a
quarter of the song's median score, or one shorter than 0.08s or longer
than 3s, which no singer produces and which a word stretched over
something else does. Flagged notes less than 2s apart share one warning.
branderson