Canon
The playing or singing of a melody (or other musical pattern) against itself.
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Fig
1: Bach proudly displays a sample of his work: a triple canon in
six parts. Haussmann (1746). |
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[Example 1: J.S. Bach, Goldberg Variations, "Canon at the Ninth," Ton Koopman. CD 707.]
The playing or singing of a melody (or other musical pattern) against itself is called canon. In its most common form, the second presentation of the melody is delayed by a specified number of notes or beats after the beginning of the first. It is, in effect, a time-delay system that causes one voice part to "echo" another.
This cannot be done with just any melody. It has to have been carefully designed so that, when sounded against itself, satisfactory harmony results. Passages in canon do not end in canon; they are either "tied off" with a cadence or are transformed into a non-canonic texture.
Canon has been obsolete at no time since its inception in the 13th century; countless examples can be found in polyphonic music written between then and the present day. Here is probably the earliest surviving canon, written in England around 1250, Sumer is icumen in:
[Example 2: Anon.: Sumer is icumen in. Hilliard Ensemble, CD457.]
The construction of a canon requires the establishment of a pitch interval, which determines the vertical distance between the lines, and a time interval, which marks the temporal distance (the "delay") between the original line and its second presentation. The first line is known as the leader, the second as the follower. Unisons, 5ths, and octaves are the most common pitch intervals. The time interval can vary greatly, ranging from a single beat to eight beats or more.
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Fig
2: pitch interval and time interval. |
Listen to the following excerpt from the Goldberg Variations (1742) by Johann Sebastian Bach. It is a two-part canon at the interval of a ninth that has a time interval of 6 beats (about two seconds):
[Example 3: Goldberg Variations, "Canon at the Ninth," CD 707.]
You have just heard an example of canon in two parts. Many canons involve not just one delayed presentation, but two, three, or even more. The greater number of statements sounding against each other, the more cunningly does the original melody have to be designed in order to result in satisfactory harmony.
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Fig.
3: Four-part canon |
Some compositions have two, even three, different canons that are performed simultaneously:
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Fig.
4: Three two-part canons combined |
Canon is not always applied to every part. It is more common to find examples that are accompanied by other lines that are not in canon. A pair of sopranos (doubled by woodwinds) perform a canon against a non-canonic background in the following excerpt from Tehillim (1981), a setting of four psalms in Hebrew by Steve Reich:
S1: Halelúhu batóf
umachól, halelúhu baminím
vaugáv; Halelúhu batziltzláy
shamáh,
S2: Halelúhu batóf umachól,
halelúhu baminím vaugáv;
Halelúhu batzil-
S1: Halelúhu batziltzláy
taruáh; Kol hanshamá tahaláil Yah,
Haleluyáh. Kol hansha-
S2: tzláy shamáh, Halelúhu
batziltzláy taruáh; Kol hanshamá
tahaláil Yah, Haleluyáh.
S1: má tahaláil Yah,
Haleluyáh.
S2: Kol hanshamá tahaláil Yah,
Haleluyáh.
Trans: Praise the Lord with tambourines and dancing, praise him with flute and strings; praise him with the clash of cymbals; praise him with triumphant cymbals. Let everything that has breath praise the Lord! Hallelujah.
The simplest and most popular form of canon is the round. "Row, Row, Row, Your Boat" is perhaps the best-known example. A round is sometimes called a 'circle,' 'infinite,' or 'perpetual' canon because the leader and follower repeat the melody at the same pitch level in an apparently endless cycle until it is broken off at will with an ending. By omitting the ending a round can, in theory, be performed for an indefinite number of times. Here is an example from the Musical Offering (1747) by J. S. Bach. In this recording the round is performed by two violins:
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Fig.
5: Musical Offering: Canon at unison |
When the follower inverts the intervals of the leader the result is called a mirror canon or a "canon in contrary motion." The following passage from Mozart's Wind Serenade in C Minor contains two canons. The first is performed by a pair of oboes; Two bassoons play the second canon. The entire passage is then repeated:
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Fig.
6: Mozart: Two mirror canons combined |
[Example 6: Mozart, Wind Serenade in C minor, mvt. 3, The Norwegian Wind Ensemble. CD 1693.]
Canonic technique offers other possibilities. In a retrograde canon (known also as a "crab canon" or "cancrizans") the follower repeats the leader in reverse. Some canons alter the melody played by the leader. In an augmentation canon the follower expands the length of each pitch; the opposite occurs in a diminution canon. A free canon has a follower that repeats selected aspects of the leader, such as its rhythm or intervals.
Techniques are sometimes combined. A mirror canon in retrograde is one possibility. The concepts of imitation, retrograde, inversion, and other canonic techniques had a profound influence on the development of twelve-tone music.
We should keep in mind that aspects of canon are sometimes utilized by music that is not in canon. Its most common trait, a beginning that is repeated in another voice part, is encountered in imitative polyphony. There, the principle of exact repetition lasts only for brief periods, however. Fugue is another technique based on the restatement of a melody in different voice parts. In fugue, unlike canon, the melody is a single short idea, and may undergo certain changes. Moreover, parts of the melody are often developed in contrasting sections known as "episodes."
The term "canon" originally meant "rule." (It is from this sense that such phrases as "Western canon" and "canonical work" derive.) During the Middle Ages and Renaissance, the melody was often written out only once in notation, with a verbal instruction or "canon" placed beneath it to tell musicians how to perform the other voice or voices. Here is an example of a canon in four parts that was written out in this way. It is a Gloria, from the Mass, and was written by John Dunstaple about 1430.
[Example 7: Dunstaple: Gloria, 4-part canon with free tenor, Orlando Consort.]
Summary:
- Canon describes the playing or singing of a melody (or other musical pattern) against itself.
- The construction of a canon requires the establishment of a pitch interval, which determines the vertical distance between the lines, and a time interval, which marks the temporal distance between the original and the restatement.
- The original line is known as the leader, its restatement as the follower.
- Canons are often accompanied by other parts that are not in canon.
- Aspects of canon can be found in music that is not in canon, such as imitative polyphony and fugue.
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Visual & Sound Materials from the Gabe M. Wiener Music & Arts Library of Columbia University |
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written by: Michael von der Linn Recording & Mixing: Christopher Bailey |
Narration:
Annalisa Poirel Technology & Design: Maurice Matiz |