This is a follow up to the blog post where I discuss basic counterpoint here:
I strongly recommend reading the above post and watching that video first. With just the few counterpoint rules demonstrated, the above video will take you pretty far. The following 2 videos take things even further and discusses the rules for other intervals besides just 3rds and 6ths.The addition rules discussed below, are summarized as follows but will make more sense after watching the video.
First we need to define some terms
- IC – Imperfect Consonances : 3rds and 6ths, major and minor
- PC – Perfect Consonances : unison, 5ths, octaves
- D – Dissonances : 2nds, 4ths, 7ths
The counterpoint rules for the above groups of intervals are:
1. You can arrive at an Imperfect Consonance (IC) by way of any other interval
IC (3rd, 6th) -> IC (3rd, 6th) PC (unison, 5th, octave) -> IC (3rd, 6th) D (2nd, 4th, 7th) -> IC (3rd, 6th)
In other words you can arrive at a 3rd or 6th by any other preceding interval.
2. You can only arrive at a Perfect Consonance by way of an imperfect consonance
IC (3rd, 6th) -> PC (unison, 5th, octave)
In other words you can only arrive at a Unison, 5th or Octave, by way of a 3rd or 6th.
3. You can only arrive at a Dissonance by an Imperfect Consonance.
IC (3rd, 6th) -> D (2nd, 4th, 7th)
In other words, you can only arrive at a 2nd, 4th or 7th by way of a preceding 3rd or 6th.
Basically, 3rd and 6th are like wild cards. They can do anything. They can follow or precede any other interval. All other intervals must be preceded by and lead to a 3rd or a 6th.
The above refers to harmonic intervals, both notes playing at the same time. For melodic intervals where notes play consecutively, only the augmented 4th and 7th intervals are considered dissonant.For a more complete explanation of the above summary, see the 2 videos below: