LA cantus firmus compositionTechnique core term Support my free tools
fixed melody used as a polyphonic basis
What is it?
Cantus firmus means fixed melody or fixed song: a melodic line used as the structural basis for polyphonic music.
What does it do?
Take a melody — borrowed or newly invented — lay it out in long, deliberate notes, and build the other voices around it. Latin for 'fixed song'. Historically it was the structural spine: in the organum of the St Martial and Notre Dame schools the chant is stretched into sustained tones while florid voices spin above it; by around 1100 the cantus firmus settled into the lowest-sounding part, which is exactly why that voice came to be called the tenor (from tenere, 'to hold'). Secular tunes served too — 'L'homme armé' was set more than forty times, twice by Josquin des Prez. The same idea became the engine of counterpoint teaching: in Fux's species method you write each new species against a given cantus firmus, which is how most composers still first learn to control a line. You can practise exactly that on this site's free cantus-firmus generator.
A slow structural pillar — often barely perceptible as a 'tune' — beneath or inside faster, more elaborate counterpoint. The ear feels a steadiness the surface activity is anchored to.
In context
cantus firmus ('fixed song'): a pre-existing melody, usually in long notes, used as the backbone for polyphony. Central to medieval organum and Renaissance L'homme armé masses (Josquin), and the given line you write against in Fux-style species counterpoint.
Equivalent terms
- IT canto fermo
- EN cantus firmus
- DA cantus firmus
- DE Cantus firmus