Cantus firmus

Definition

A cantus firmus is a pre-existing melody that serves as the foundational layer in polyphonic music, often used as the basis for elaborate counterpoint. This technique allows composers to construct new compositions by building harmonies and additional melodic lines around this fixed tune, creating a rich tapestry of sound. The cantus firmus is usually presented in a slower tempo and often found in sacred music, contributing to the overall structure and coherence of the piece.

5 Must Know Facts For Your Next Test

1. Cantus firmus is often derived from Gregorian chant, which provides a recognizable melody for further development.
2. In two-part writing, one voice typically carries the cantus firmus while the other voice weaves around it, creating harmonic support and counterpoint.
3. Composers from the Renaissance and Medieval periods extensively used cantus firmus to structure their compositions, providing a sense of unity and direction.
4. The cantus firmus is usually presented in long note values, contrasting with the more rhythmically active lines that surround it.
5. This technique laid the groundwork for more complex forms of polyphony, influencing the development of Western music through the Baroque period and beyond.

Review Questions

• How does a cantus firmus function within a two-part composition?
  • In a two-part composition, the cantus firmus serves as the primary melodic line upon which the second voice builds its counterpoint. This fixed melody typically has longer note values and is presented in a slower tempo, providing a stable foundation. The accompanying voice explores harmonic variations and rhythmic activity, creating an interplay that enriches the overall texture of the music while highlighting the cantus firmus.
• Discuss how composers might manipulate a cantus firmus to create interest in their compositions.
  • Composers can manipulate a cantus firmus in various ways to generate interest, such as altering its rhythm, transposing it to different keys, or using inversion techniques. They may also employ techniques like augmentation or diminutions, which involve stretching or compressing the original melody's duration. These strategies allow composers to maintain the integrity of the original melody while introducing variation and complexity to the surrounding polyphonic textures.
• Evaluate the impact of using a cantus firmus on the evolution of Western music from the Medieval period to the Baroque period.
  • The use of a cantus firmus significantly impacted the evolution of Western music by establishing foundational practices in counterpoint and harmony. During the Medieval period, it facilitated early forms of polyphony and allowed composers to explore intricate relationships between voices. As music transitioned into the Renaissance and Baroque periods, these practices matured, leading to more sophisticated harmonic structures and complex textures. The reliance on a cantus firmus provided composers with a framework for creativity, influencing not just composition techniques but also shaping musical forms that continue to resonate throughout Western music history.

Related terms

Counterpoint: The relationship between voices that are independent in rhythm and melody but are harmonically related.

Polyphony: A musical texture consisting of two or more independent melodic lines played or sung simultaneously.

Organum: An early form of polyphony based on plainchant, where additional melodic lines are added to a cantus firmus.