Here I present: Arthur C. Edwards, “Practical Lessons Melody Writing”, 1966. CANTUS FIRMUS.
INTRODUCTION.
A cantus firmus fits perfectly with melody writing in a major scale and 4/4 time, with a few classical caveats.
Here’s how it’s traditionally understood and how you’d write one.
What a Cantus Firmus Is
A cantus firmus (“fixed song”) is a simple, stepwise melody used as the structural foundation for counterpoint.
Classical traits (Fux / species counterpoint tradition):
Major or minor scale
Conjunct motion (mostly steps)
Limited range (usually a 6th to an octave)
No rhythmic complexity
Clear tonal center
Rhythm in 4/4 Time
Historically, cantus firmus is often written in whole notes (one note per measure).
So in 4/4, this works cleanly:
1 note per bar
Each note = semibreve (whole note)
This makes it ideal for:
Teaching counterpoint
Harmonization exercises
Modal or tonal analysis
Major Scale Guidelines (Practical Rules)
If you’re writing a tonal (not modal) cantus firmus in a major key:
Begin on the tonic
End on the tonic
Use mostly stepwise motion
Use leaps sparingly:
Prefer 3rds
Any leap should be followed by stepwise motion in the opposite direction
Avoid:
Tritones
Repeated notes (some schools allow one)
Keep a strong sense of diatonic clarity.
Example (C Major, 4/4)
Each note lasts one full measure:
Cantus Firmus:
C D E G F E D C.
Characteristics:
Starts and ends on tonic (C)
Mostly stepwise
One expressive leap (E → G), resolved downward
Clear tonal gravity
When to Use 4/4 Cantus Firmus
Perfect for:
Species counterpoint (1st → 5th)
Chorale-style harmonization
Teaching melodic discipline
Compositional “skeletons”
………………………………………………………………
Here’s a theoretical, cantus-firmus–style reading of the opening 8-bar period of “Over the Rainbow”, transposed to C major, without reproducing the copyrighted melody itself—instead using scale degrees, function, and contour.
Context
Composer: Harold Arlen
Style: American songbook lyricism with classical voice-leading instincts
Meter: 4/4
Key (here): C major
Form: 8-bar period (antecedent + consequent)
Although not a literal cantus firmus, the melody behaves like an expressive, expanded cantus.
Antecedent Phrase (mm. 1–4)
Function: Statement → half cadence
Contour: Expansive upward leap, then gentle descent
Scale-degree outline (C major):
Cantus Firmus:
1 → 8 → 7 → 6 → 5
The famous opening octave leap (1 → 8) is exceptional by cantus-firmus rules, but:
It is immediately compensated by stepwise descent
Strong sense of tonic → dominant
Ends with incompleteness (cadential dominant)
🎼 Cantus-firmus parallel:
A single large expressive leap, then strict stepwise correction.
Consequent Phrase (mm. 5–8)
Function: Answer → authentic cadence
Contour: Smaller gestures, closing descent
Scale-degree outline:
Cantus Firmus:
5 → 6 → 5 → 4 → 3 → 2 → 1
More conjunct motion
Registers lower than the antecedent peak
Clear tonic resolution
Final descent reinforces tonal gravity
🎼 Cantus-firmus parallel:
Controlled descent to the final with no ambiguity.
Why This Works as a “Modern Cantus”
Cantus Firmus Principle
Arlen’s Adaptation
Clear tonic opening
Begins unequivocally on scale-degree 1
Limited dissonance
All tensions are melodic, not harmonic
Stepwise predominance
After the leap, motion is almost entirely conjunct
Structural cadence
Antecedent half cadence → consequent authentic cadence
Singable line
Breath-length phrases, narrow tessitura (after the leap)
Summary
The opening 8 bars of “Over the Rainbow” function as:
A lyrical, 20th-century cantus firmus with one sanctioned expressive exception (the octave leap).
Harold Arlen essentially breaks one rule to create magic—then obeys all the others to make it inevitable.
