Yes, learning counterpoint is an old way composers have learned the basics of composition but I believe it is a skill all composers, songwriters, and producers should have in their tool belt.
Cantus firmus literally means “fixed melody” which just means the main melodic line that all other voices will be based on. Think of it as the first layer in a multilayer music composition.
In this article I’ll explain what the cantus firmus is and how it works but more importantly how learning the principles of writing a cantus firmus, and counterpoint, will improve your creative skills.
Quick overview of cantus firmus
This practice comes from at least as early as the 13th century and was primarily used in sacred chant music. Over the centuries of it’s usage, the cantus firmus has moved from the top voice to the lowest voice to finally settle in a middle voice called the “tenor” (tenor means “to hold”, as in holding the music together).
I’d like to pause and just note that the idea of the cantus firmus as a way to organize, build, shape, and teach music has so far lasted over 700 years! That fact alone should make anyone creating musician take notice (I also strongly believe that other disciplines might be able to use some of the principles found in the cantus firmus in their approach to their own fields, but that is a topic for another article).
As a pedagogical method, counterpoint (the cantus firmus) can stand tall because pretty much every successful and famous classical composer learned through this method at one point or another. It’s incredible that counterpoint has been a through line of success across so many geographies, individuals, times, and musical tastes. All that’s to say, this is great stuff to learn if you are interested in creating music – whether that is writing pop songs or string quartets!
Lastly, cantus firmus forms the basis for Western music’s polyphonic writing. Other cultures also have polyphonic music that is built in entirely different ways – yet again, another topic for another article.
Some examples of cantus firmus
Before explaining all the “rules” that go into a cantus firmus, I’d like to point out that these rules were created after the fact. Most music theory explains music that is already written – it doesn’t necessarily predict. Music theory typically takes a look at music and tries to explain why the music works. Same goes for the rules of counterpoint.
The music is always first. Rules and theories come after.
– Common Knowledge
Also, keep in mind cantus firmus and counterpoint began as vocal music. With that out of the way, let’s listen to a few examples.
The first example is from the most famous of counterpoint books Gradus ad Parnassum by Joseph Fux.
Another example, this time composed by me.
You may note many things about these short lines of music, but one thing should stand out – it only has one rhythmic value!
You should be able to hear the following characteristics of a cantus firmus:
- it’s a melody within a fairly narrow range
- it has virtually no rhythmic variety
Music of the time certainly had more than one rhythmic value but rhythmic notation in Europe took a while to catch up – remember music first!
Here is a nice two-part example from Pérotin, a French composer from the 1200s. Among many other features to notice, you may notice there is variety of rhythm.
Why learn to write a cantus firmus?
I already enumerated the reasons to learn counterpoint but more specifically, the cantus firmus can help in melodic writing. Many of the rules that shape a cantus firmus are still found in contemporary melodic writing. Of course, there are plenty of exceptions, I’m not saying all melodies follow the cantus firmus approach, but there are certain principles that have managed to persist. Aesthetically, what Western music deems to be a “good” melody, has some parallels with cantus firmus. This will become clearer as I show you the way a cantus firmus is composed.
How to write a cantus firmus in 5 steps
To compose a cantus firmus, the only prerequisite you need is to be able to place notes on a staff, know their pitch, and be aware of a few intervals. Understanding intervals is a critical skill and I highly recommend reading my interval article to get that skill under your belt.
Step 1 – just try!
Just try writing something that mimics the examples above. This is just to get you comfortable setting up the 8 -14 measures and getting notes on a page. I highly encourage you to always play back your work, whether that is on an instrument or by singing.
Step 2 – the beginning and the end
Whatever note you started on is the note you must end on. So, it’s a bit like fill in the blank. Setup your measures, place your first note, and then place your final note.
Step 3 – plan your climax
Climax in this type of writing just means the highest note. There should be only one highest pitch. Past the half-way mark of your cantus firmus (if you have 10 measures than from the 6th measure onward) and before the 3rd to last measure, make that your highest note. This is now the climax of your cantus firmus.
For example, if you have an eight-measure melody, you can place the climax in measure 5.
Example two, if you have an eleven-measure melody, you can place the climax in measures 6, 7, or 8.
If you like, you can take the total number of measures and multiply by 0.7 and that should tell you pretty well where you climax should be placed. This is just a guide not an absolute! There are always exceptions.
| Number of measures | X 0.7 | Climax |
| 8 | 5.6 | 5 |
| 9 | 6.3 | 6 |
| 10 | 7 | 7 |
| 11 | 7.7 | 7 |
| 12 | 8.4 | 8 |
| 13 | 9.1 | 9 |
| 14 | 9.8 | 9/10 |
The placement of the climax is one of those traits that has continued until this day. Many pieces, pop or otherwise, place their climax near the end of the song, much like the placement we find in cantus firmus.
Step 4 – steps and leaps (skips)
There are two types of motion from one note to another – steps and leaps. A step means the note is either one line or space higher or one line or space lower. A leap is anything more than an interval of a 2nd. An example helps here:
Leaps are treated differently than steps. In general, if your melody leaps up by a minor sixth (8 half steps) or octave it must fall back down by a step.
If your melody leaps down by an octave, it must move back up by step. This is one of those melodic principles that has persisted until today. Many pop melodies follow the “rule” that after leaping up or down the melody needs to move in the opposite direction by step.
Here is a cantus firmus from Joseph Fux that shows a couple of leaps in the same direction are sometimes resolved by stepping in the opposite direction. In general, you do not want your melody continuing up or down for too long – breaking up the direction of the melody after it has moved in the same direction for three-four notes is a good rule of thumb.
There are some intervals you must not create when you leap. The following are “forbidden”:
- tritones (6 half steps)
- minor 7th (10 half steps)
- major 7th (11 half steps)
- any interval greater than an octave (12 half steps)
You should already have your first, last, and climax measures filled in, now use steps and leaps to fill in the rest of the measures to connect the notes.
Step 5 – don’t outline a tritone
Be careful to make sure your melody does not outline a tritone (augmented 4th/diminished 5th).
Completed cantus firmus
You have now completed your first cantus firmus! Here are the steps right next to each other:
Now you can play your cantus firmus!
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