Writing a Canon
Imitation, or repetition, is an important element of any good musical composition or improvisation. In popular music, especially rock music, this element known as the "hook:" a repeating phrase that catches or 'hooks' the ear and instantly pulls the listener in—rather like a fish being hooked by the bait. The melodic fragment, usually in the bassline or in the melody, becomes a hook due to its repetition. I'm sure you can think of a lot of pop tunes that have great hooks. Pink Floyd's Money, which we listened to in chapter one, has one such bassline hook. The Beatles' Day Tripper is another great example. You could I'm sure make your own list.
In classical music, the "hook" is equally important, although it tends to be thought of as imitation, especially in the form of "imitative counterpoint," when one voice in a many-voiced texture imitates another. In this context, we could think of the opening motif of Beethven's Fifth Symphony as a "hook:" is certainly grabs the ear and never lets go as it goes through its many iterations and repetitions. Beethoven rocks!
Imitation is also used within a series of musical phrases. In this instance,
a short melody or melodic fragment is re-stated at another pitch level,
usually two or three more times. This is known as a musical sequence. We'll
discuss the sequence on a later page when we get more deeply into melodic
shape over a changing harmony.
Of all these techniques, the musical canon (or round) is the simplest imitative technique and is the first step in learning how to create imitative passages within a composition. A musical round is usually written as a single melody, with multiple entrances. When the melody reaches a particular point, the next voice enters with the same material, and a cascading effect is reached. We heard a few of these at the beginning of the semester, with the chants from Libana, and you can go back there and listen to them again if you like.
Canons are like rounds, but in the case of modal canons in two parts, you only need concern youself with the previous phrase—these types of canons do not cascade on top of each other like a true round. Only the most recent phrase is repeated and must be harmonized with a new phrase, which in turn becomes the repeated phrase that is then harmonized with a new phrase. This could go on for a very long time, like two mirrors facing each other and reflecting an image into infinity.
Two-part modal canons are thus the easiest to write, and you have enough background now to give it a try.
The procedure is as follows.
- Begin with two lines of music, both in the treble clef.
- Write out a short, simple melody, about two measures long in one voice (use the upper voice).
- Re-write the same melody in the lower staff, then write an appropriate counterpoint above it, according to the rules of counterpoint.
- With canons, it is OK to cross voices.
- Continue this pattern for three, four or more repetitions.
- When you want to conclude the canon, either allow the last voice to conclude on its own, or write a short cadence in two part counterpoint, after the last imitative voice has concluded.
Here is an example canon, just composed for this page. It is squarely in the Dorian mode, with an emphasis on the B natural but with a clear sense of D as the tonic center. Notice the exact imitation between the labelled sections (a,b,c,d,e, and f). Occasional, voices merge into unisons as they cross. There is a balance of mainly thirds and sixths, a few fifths and a few prepared dissonances. In this example, the canon is brought to a close without bothering to repeat the phrase labelled as 'f.' Be sure to listen to this a number of times and hear the voices interact as you watch the score.
Next: 4H Dissonant Counterpoint