F Lydian
Four quarter notes per measure against each whole note of the cantus firmus. The final measure is a single whole note.
Cantus firmus: Fux, Gradus ad Parnassum (Figure 59) — 12 measures
Your line: written above the cantus firmus
To pass: complete every measure with no rule violations and score at least 80/100
How Third Species works
You place quarter notes: four per measure. The first quarter of each measure is the strong beat and must be consonant.
The other quarters may be dissonant when they pass or turn by step between consonances.
Third species also allows the nota cambiata: a five-note figure (step down to a dissonance, leap down a third, then two steps up) that is exempt from the normal step rule.
With this many notes, melodic shape matters most — mostly stepwise motion with a clear single climax.
The rules
- First beat of each measure must be consonant. The downbeat quarter forms a consonance with the cantus firmus.
- Dissonant quarters move by step. Dissonances must be approached and left by step (passing or neighbor tones), except within a valid nota cambiata.
- Mostly stepwise motion. Third species lines should flow — aim for well over half of your motion to be by step.
- Quarter notes throughout. Keep the species rhythm: quarter notes in every measure, with a single whole note at the end.
- Begin and end on a perfect consonance. The first and last intervals must be a unison, perfect fifth, or octave against the cantus firmus (a fifth below the CF is not allowed when writing underneath it).
- No parallel or hidden fifths and octaves. Two voices may not move in the same direction into a perfect fifth or octave. Consecutive perfect intervals of the same size destroy voice independence.
- Singable melodic intervals only. No melodic tritones, sevenths, or leaps larger than an octave. Your line should be singable.
- Recover from leaps by stepping back. After a leap (especially a large one), change direction and move by step to fill in the gap.
- Aim for a single climax. Your line should have one highest note, ideally somewhere in the middle of the phrase.
- Keep the line varied. Avoid long chains of parallel thirds or sixths, and avoid mid-phrase unisons with the cantus firmus.
- Prefer contrary motion. Moving against the cantus firmus keeps the two voices independent. Aim for contrary motion at least ~40% of the time.
Tips
- • Scales and scale fragments are your friend — third species is essentially controlled scalework.
- • Place the leap of the nota cambiata only where the second note is dissonant and the fourth is consonant.
- • Avoid outlining a tritone across a measure of quarters.