Guidelines for Two-part Writing (Counterpoint in the style of C.P.E. Bach, F.J. Haydn, and many of their central-European contemporaries)
Adapted from C.P.E. Bach’s Essay on the True Art of Playing Keyboard Instruments (tr. & ed. by William Mitchell; New York: Norton, 1949), and Kennan’s Counterpoint (4th ed.; London: Pearson, 1998)
1. PERFECT CONSONANCES between bass and treble should be
avoided on strong beats, except
when both parts arpeggiate simultaneously, suggesting a larger number of voices
at the beginning of the phrase, or at cadences
when P4 is part of a “K64”; in this case the P4 is really an NCT, functioning as a dissonance
other cases when P4 acts clearly as a dissonance (as in a suspension)
avoided in succession at any level of metric structure, except
when both parts arpeggiate simultaneously, suggesting a larger number of voices
at phrase endings, ONLY with conventional cadences involving P5-P8 or P8-P5
at phrase beginnings and endings, when a clear feeling of announcement is the aim
on the weak beats of successive bars or weak subdivisions of successive beats
approached by oblique or contrary motion, except
when both parts arpeggiate simultaneously, suggesting a larger number of voices
direct motion P5-P8 or P8-P5 is OK in conventional cadences
in sequences only: on the weak beats of successive bars or weak subdivisions of successive beats
approached by stepwise motion in at least one part, except
when both parts arpeggiate simultaneously, suggesting a larger number of voices
in sequences only: on the weak beats of successive bars or weak subdivisions of successive beats
2. DISSONANCES between bass and treble should be
resolved by step, even if not right away
resolved to a note that clarifies the harmony, even if not right away
approached by oblique or contrary motion
one of the non-chord tone types: N (neighbor, including Camb. and Ch.), A (appogiatura), E (escape tone), P (passing tone), S (suspension), or R (retardation).
3. The majority of intervals formed between the bass and treble chord tones should be IMPERFECT CONSONANCES
4. Rhythmic and motivic considerations
Do not halt motion in both voices at the same time
Emphasize alternations in activity between complementary voices, so that one voice pauses or slows while another contains denser activity.
Make sure each phrase has a good balance of oblique, contrary, and parallel motion.
Reduce, reuse, recycle: Produce a texture with an overall stylistic unity by basing it on a small amount of material — take a single motive and make use of its rhythm repeatedly, rather than diversifying and varying the character.