A Aeolian
One whole note in every measure — one of your notes against each cantus firmus note.
Cantus firmus: Fux, Gradus ad Parnassum (Figure 23) — 12 measures
Your line: written below the cantus firmus
To pass: complete every measure with no rule violations and score at least 85/100
How First Species works
The gray notes are the cantus firmus ("fixed song") — a given melody you compose against. It never changes.
Click a square on the piano roll to place a whole note in that measure. Click a note to remove it, or drag it to move it in pitch and time.
Every interval you form against the cantus firmus must be consonant: unison, 3rd, 5th, 6th, octave, or their compounds. There is no dissonance anywhere in first species.
The checker on the right updates as you write. Red marks are rule violations, amber marks are style warnings.
The rules
- Every interval must be consonant. Only unisons, thirds, fifths, sixths, and octaves against the cantus firmus. No seconds, fourths, or sevenths.
- 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
- • Sketch the last two measures first: approach the final perfect interval by contrary stepwise motion (e.g. 6th → octave, or 3rd → unison).
- • Use mostly imperfect consonances (3rds and 6ths) in the middle — perfect intervals sound hollow and invite parallels.
- • Move by step most of the time; save leaps for moments that need energy.