We write four quarter notes against one whole note.

Remember that whole note = 60-72, so quarter notes should feel as sixteenth notes in a baroque allegro: lively!

Remember the "old" hard rules:

1. All (untied) downbeats must be consonant
2. All perfect intervals must be approached by  contrary or oblique motion
3. Direct repetition of a whole contrapuntal combination is to be avoided (read forbidden... ;-) )
4. No skips to or from dissonances
5. No repeated notes in the added voice
6. You may begin with a half note rest, but the first sounding note must make a perfect consonance with the CF

Hard rules (new)

1. First and third quarter notes should be consonant
2. Second and fourth may be dissonant if they are passing or lower neighbors
3. Less than half of the melodic motions should be skips
4. Avoid repetition of lower neighbors
   
   

Idioms: CAMBIATA 

Idioms are specific (stylistic) patterns by which a hard rule may be broken.

1. The dissonant in the cambiata should be approached by a descending step and be on the second quarter
2. After the dissonant a descending third follows to a consonant interval
3. The descending third is followed by at least two ascending steps.
4. Possible patterns above: 8-7-5-6 and 6-d5-3-4
5. Possible pattern below 3-4-6-5