Movement will be primarily in quarter notes, with added eighths and some halves. Less frequently you can use sixteenths, usually in pairs but sometimes as dotted eighth-sixteenth groups.
Exercises in realizing harmony from Roman numerals or from figured bass will be evaluated according to the principles defined as the "Bach vocal" style, one of the style sets built into Counterpointer. Bach's chorale harmonizations are often used as a model of 4-part tonal writing for voices. The below rules offer a technical approximation of his style in the chorales.
Movement will be primarily in quarter notes, with added eighths and some halves. Less frequently you can use sixteenths, usually in pairs but sometimes as dotted eighth-sixteenth groups.
The fourth is treated as a dissonance if formed with the bass.
Augmented 4ths and diminished 5ths not involving the bass are treated as consonant if both notes are "essential" (i.e. part of the chord).
Dissonance should not be approached by leap, except for
An unaccented leap to an anticipation
A leap in a cambiata figure
A leap between essential tones (and that leap must be downward)
A leap in an appogiatura figure, either accented or not
Avoid accented dissonances except in these cases:
The suspension. The suspension's preparation tone must be unaccented, and you should avoid using the note of resolution in the dissonant sonority. The suspension's normal tie can be omitted (a repeated-note suspension) and it can in rare cases resolve upward.
Accented passing or neighboring tones
An accented seventh should resolve downward, whether inverted to a second or not.
Dissonance should be resolved immediately by step, except in these cases:
The cambiata and double auxiliary figures
The escape tone (which must be downward)
An essential tone may rarely intervene between a dissonance and its resolution.
Two successive dissonances may be allowed if they are quick, stepwise in the same direction, and the first one is unaccented.
Minor and diminished sevenths will be considered essential dissonances if part of a chord.
Avoid parallel fifths and octaves between adjacent notes, except
They can be allowed sometimes if syncopated.
Parallel fifths may be allowed if they are contrary (one fifth moving to another in
contrary motion) and one voice is inner.
Avoid parallel fifths and octaves between notes on adjacent accents, except
They are allowed if the faster leaps by more than a third from the first perfect interval.
Avoid direct fifths or octaves, except
The are allowed if one voice is inner and the exposed voice moves by step.
They are allowed at a cadence.
A direct 5th or 8va may be allowed in the outer parts in 4 voice writing if the upper voice moves by step.
Avoid parallel fourths, except
When combined with 6ths to form first inversion triads
Whey may be allowed if one of the two notes is unessential
Each chord should include a third, except An "empty fifth" is allowed if the third appears in the same beat. Avoid doubling the seventh of a chord. Avoid doubling the leading tone in a dominant harmony.©2011 Ars Nova Software, LLC