1.2 Second Species — Two Notes per Chord-Zone
Definition. Second species places two notes in the added voice per chord-zone. The first note is on the chord-graph “downbeat” (the moment of chord arrival); the second note is on the second half of the chord-zone. The second note may be a passing tone or a chord tone.
What this teaches. Second species introduces melodic motion within a chord-zone. The student learns to use passing tones and neighbor tones — the OTH analog of dissonance treatment — within the chord-graph framework. It also teaches the use of non-chord tones in OTH: notes that are not chord tones of the current chord but that resolve by single semitone to a chord tone of the next chord.
Setup. A chord-graph path of 4-6 chords. The added voice plays a chord tone on the first half of each chord-zone; the second half may be a chord tone or a non-chord tone (passing or neighbor).
Step-by-step procedure
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Begin with a first-species line. Lay out the cantus firmus and an acceptable first-species added voice. This is your skeleton.
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Identify opportunities for melodic motion. Within each chord-zone, ask: between the first-species note in this chord and the first-species note in the next chord, is there an intervening chord tone or stepwise non-chord tone that would create a smoother melodic line?
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Insert passing tones for chord-tone-to-chord-tone leaps of 3+ semitones. A leap of a third or more between adjacent first-species notes is a candidate for a passing tone. Example: first-species line G4 → Bb4 (a minor third, 3 semitones). Insert A4 as a passing tone: G4 (chord tone) → A4 (passing) → Bb4 (chord tone of next chord). The A4 is a passing tone if it does not violate the underlying chord (it must be either a chord tone or a non-chord tone that resolves by step).
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Use neighbor tones for variety. A neighbor tone is a non-chord tone approached and left by step in opposite directions. Example: holding C5 over chord 2 and chord 3 (a common-tone hold) becomes more interesting with C5 → D5 → C5 (upper neighbor) within the chord-zone of chord 2, before the C5 in chord 3.
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Pay special attention to the OTH leading-interval-pair. When the added voice is moving by single semitone toward a chord tone of the next chord — and the cantus firmus’s moving voice is doing the same — this is a leading-interval-pair: two voices each moving by one semitone in coordinated motion. This is OTH’s strongest cadential gesture. In second species, exploit it at the cadence.
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End the cadence on a chord tone of the final chord, approached by step. Second species cadences are smoother than first species because the added voice has had two notes per chord-zone leading up to the cadence.
Worked example
Cantus firmus: same five-chord progression (Q777 → Q877 → Q787 → Q877 → Q777).
First-species added voice: D5 → D5 → Eb5 → D5 → D5 (the line from §1.1).
Second-species elaboration:
| Chord | Beat 1 | Beat 2 | Notes |
|---|---|---|---|
| 1 | D5 | D5 | Hold (no melodic motion needed yet) |
| 2 | D5 | C5 | Step down to C5 (passing tone leading to Eb5? Wait — D5 → C5 → Eb5 is a step down then a third up. Better: D5 → Eb5 (step up to anticipate chord 3). |
| 3 | Eb5 | D5 | Step down to D5 (the chord 4 pitch); creates contrary-motion-like figure |
| 4 | D5 | D5 | Hold |
| 5 | D5 | D5 | Held cadence — OBLIQUE motion to cadence |
Revised line, beat by beat: D5–D5 / D5–Eb5 / Eb5–D5 / D5–D5 / D5–D5.
Check.
- Every “beat 1” note is a chord tone. ✓
- The “beat 2” notes: chord 2 beat 2 = Eb5, which is not a chord tone of Q877 = {C,D,G,Bb}. But Eb5 is a chord tone of the next chord (Q787 = {C,Eb,G,Bb}). So Eb5 functions as an anticipation — it sounds the next chord’s tone before the chord arrives. This is a legitimate non-chord-tone usage. (In Fuxian terms: anticipation. In OTH terms: leading-tone-pair with the cantus firmus’s D→Eb edge, shifted earlier.)
- The chord 3 beat 2 = D5, which is a chord tone of the next chord (Q877 = {C,D,G,Bb}). This is also an anticipation.
So the second-species line uses anticipations to create melodic motion; the line is now: D5 D5 D5 Eb5 Eb5 D5 D5 D5 D5 D5. More interesting than the first-species version.
Common errors in second species
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Unprepared non-chord tones. A non-chord tone that doesn’t resolve by step (or doesn’t anticipate a chord tone of the next chord) is not legal in second species. Example: D5 → F5 → Eb5 (where F5 is neither a chord tone nor a stepwise approach to anything). The F5 is an unprepared dissonance.
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Too much motion. Second species is restrained — one note added per chord-zone. Adding three or four notes pushes you into third species.
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Forgetting the contrary-motion cadence. A second-species cadence should still resolve in oblique or contrary motion. If your beat-2 of the penultimate chord moves in parallel with the cantus firmus, you’ve lost the contrary-motion feel.
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Passing-tone collisions. Inserting a passing tone that is a chord tone of the current chord is fine; inserting one that creates a tritone with another voice is risky. Check for tritones and either resolve them properly or pick a different passing tone.