Species number claim must match the actual note-to-CF rhythmic ratio

A species exercise's stated species (1-5) must match the actual ratio of counterpoint notes to each cantus-firmus note: 1st species = 1 CP note per CF note; 2nd species = 2 per CF note (or 3, in an explicitly triple-meter variant); 3rd species = 4 per CF note (or 3 in triple meter); 4th species = 1 per CF note but SYNCOPATED (CP onset does not align with the CF onset); 5th species ('florid') deliberately mixes ratios/rhythms of the first four within one exercise. A lesson labeled '2nd species' whose CP voice actually runs in continuous eighth notes (8 per CF note) is mislabeled and teaches the wrong ratio as an example of the stated species.

Metadata declares `speciesExercise.species = 2`, but the authored CP durations yield 4 CP onsets per CF note (actually 3rd species) — the stated species and the notated rhythm disagree.

Fux (Gradus ad Parnassum) — the five species are DEFINED by their note-to-CF ratio and rhythmic placement, per Jeppesen's modern codification.

This rule can be decided from pitches, durations and voices — no layout required. A validator can check it before anything is drawn.