Guidelines for writing a 2-part invention
- Compose an invention in the style of Bach using your own plan, the plan in EXERCISE 18-5, or the plan for Bach's C major invention.
- Refer to Owen's Modal and Tonal Counterpoint chapter 18 for guidelines about structure.
- Write 2 parts, but imply triads and seventh chords.
- Write NO Perfect Parallels or parallel dissonances.
- Write NO succesive perfect unisons, fifths, or octaves in contrary motion.
- In authentic and deceptive cadences, resolve scale degree 7 to 8 and scale degree 4 to 3.
- Resolve chord 7ths down by step.
- Resolve tritones properly. (The A4 resolves to a 6th and the d5 resolves to a 3rd.)
- Resolve altered pitches by ½ step in the direction of their alteration.
- Avoid augmented or diminished melodic intervals unless a 7th chord or diminished triad is outlined.
- Follow large melodic leaps (greater than a 5th) by step in the opposite direction.
- Do not approach a chordal seventh by a descending leap.
- Do not cross or overlap voices.
- Do not approach perfect harmonic intervals by parallel or similar motion. Two exceptions:
- Perfect Fourths
- Horn Fifths
- Double NO active tones, i.e. the leading tone, altered tones or 7ths of 7th chords.
Assignment 1 — Exposition / Episode / Cadence*
Assignment 2 — Revise the first assignment and compose the remainder of the composition.
Assignment 3 — Revise the invention once more.
For all 3 assignments, please identify all harmonic intervals. Circle and identify all dissonances.
* See 2-part Counterpoint... and 2-part Counterpoint Endings.
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