What it is
In second species the counterpoint has two half notes against each whole note of the cantus. The downbeat (first half note) must be consonant; the upbeat (second half note) may be consonant or a passing dissonance. This is the first time dissonance enters the method: in a controlled way, on a weak beat and by step.
Rules
- Beginning: you may start with a half rest, then a perfect consonance (unison, fifth, octave; fifth only above).
- Downbeat: always consonant.
- Upbeat: consonant or a passing note, that is, a dissonance reached by step and left by step in the same direction, between two consonances. Example over E4: G4 (third) – A4 (fourth, dissonant) – B4 (fifth on the next downbeat).
- No repeated notes: two equal half notes in a row break the species.
- Fifths and octaves: forbidden between an upbeat and the following downbeat if consecutive; also to be avoided on consecutive downbeats when only a small leap (a third) separates them: they are heard as parallels.
- Unison: allowed on the upbeat, not on the downbeat (except at the beginning and end).
- Cadence: penultimate bar with a fifth on the downbeat and a major sixth on the upbeat (counterpoint above: B4–C#5 over E4), or a fifth and a minor third (below: A3–C#4 below E4).
- Last bar: a whole note on the perfect consonance.
Example in D Dorian, counterpoint above
Cantus: D4 F4 E4 D4 G4 F4 A4 G4 F4 E4 D4
Counterpoint (two half notes per bar):
| Bar | Cantus | Downbeat | Upbeat |
|---|---|---|---|
| 1 | D4 | rest | A4 (5) |
| 2 | F4 | D5 (6) | C5 (5) |
| 3 | E4 | G4 (3) | A4 (4, passing) |
| 4 | D4 | B4 (6) | D5 (8) |
| 5 | G4 | B4 (3) | E5 (6) |
| 6 | F4 | D5 (6) | C5 (5) |
| 7 | A4 | F5 (6) | E5 (5) |
| 8 | G4 | B4 (3) | C5 (4, passing) |
| 9 | F4 | D5 (6) | A4 (3) |
| 10 | E4 | B4 (5) | C#5 (6) |
| 11 | D4 | D5 (8) |
- The passing dissonances (A4 over E4, C5 over G4) are reached and left by step in the same direction.
- The fifths on the upbeats (C5 over F4, E5 over A4) are followed by thirds or sixths: no succession of perfect intervals.
- The climax F5 appears only once.
Functions of the upbeat
- Passing: fills in a leap of a third on the downbeat (G4–A4–B4).
- Consonant leap: changes register or position (B4–D5); useful to prepare contrary motion.
- Substitution: a consonant upbeat can turn an unfortunate downbeat succession (two fifths) into a correct one, provided the leap is large (a fourth or more) and the new interval is different.
Typical errors
- Dissonance on the upbeat reached by leap: it is not a passing note, it is an error.
- Dissonance that changes direction (C5–B4–C5 over G4 with B4 dissonant): in second species Fux does not admit the dissonant neighbor note.
- Downbeat fifths disguised by an intermediate third.
- A line that moves only by consonant leaps on the upbeat: it sounds fragmented.
Modern application
- Pop and funk bass lines: the passing note on the weak beat (C–D–E under C and Em) is the heart of walking lines and melodic basses.
- Strings in soundtracks: cellos in half notes with passing notes on the weak beats under a brass chorale make the harmonic motion smoother.
- Choirs: second voices in second species give movement to a slow chorus without disturbing the main melody.
Related topics
Second-species counterpoint, non-chord tones, parallel fifths and octaves, modal third species.