Crab Canon

Oracolo wrote:

...it's almost scary, what kind of thing is it?

Cancer, or rather "crab," or an animal that walks... backwards (I know, the crab walks sideways, but... poetic license); are you starting to understand?

Cancrizans canon (or retrograde canon) is one where the following voice is nothing other than the preceding voice in reverse.

Never mind

But how many types of canon exist?

Carlos wrote:

Cancer, or "crab," or an animal that walks... backwards (I know, the crab walks sideways, but... poetic license); are you starting to understand?

Your example made me think of the zodiac signs

carletto wrote:

But how many types of canon exist?

In addition to the crab canon which is the subject of the topic, there are:

Spiral canon

Fan canon

Accompanied canon

Canon at the ninth

Canon at the fourth

Canon at the fifth

Canon at the second

Canon at the sixth

Canon at the seventh

Canon at the third

Mirror canon

Canon at the octave

Canon at the unison

Direct canon

Enigmatic canon

Finite canon

Infinite or perpetual canon

Canon by augmentation

Canon by diminution

Canon by contrary motion

Rhythmic canon

Canon without accompaniment

Many are treated in the text by Sarah Colombo

http://www.sarahcolo...bblicazioni.php

You can also find a lot of examples in the book "Canons through the centuries" published by Carrara edited by Giorgio Ubaldi

http://www.edizionic...o-i-secoli-5166

Some useful links

http://www.giorgiopa...m/countpts.html

http://imslp.org/wiki/111_Canons_in_All_Minor_and_Major_Keys_(Reger,_Max)

Frank wrote:

Fan canon

What is it?

The mensuration canon (or fan canon) is an infinite canon (meaning it can restart from the beginning infinitely many times) in which each repetition of the theme occurs in a different key.

In its most common form, it is a two-voice canon, the first of which modulates to the upper fourth halfway through, at which point the second voice begins; thus, after having stated the canon theme in its entirety, by restarting from the beginning, each voice finds itself one tone below the previous statement ... from which the Latin name "canon per tonos" for this particular contrapuntal form originates.

Natan wrote:

The mensuration canon (specifically the 'fan' or 'tonal' canon) is an infinite canon (meaning it can restart from the beginning infinitely many times) in which each repetition of the theme occurs in a different key.

In its most common form, it is a two-voice canon, the first of which modulates to the upper fourth halfway through, at which point the second voice begins; thus, after having stated the canon theme in its entirety, by restarting from the beginning, each voice finds itself one tone below the previous statement ... from which the Latin name "canon per tonos" for this particular contrapuntal form originates.

Note the series of twenty-four passacaglias for guitar by Angiolo Michele Bartolotti (c. 1615–1696); they are constructed more or less like this. Each passacaglia begins in one key and ends in that of the next piece, according to the circle of fifths. Perhaps to better convey the idea of circularity, the first passacaglia, instead of being in C major, is in B-flat minor (or G-sharp minor, depending on whether the instrument was tuned according to the "new" or "old" tuning).

... but perhaps it is another type of composition

The most beautiful example of a “rogan canon” is found in Bach's musical output.

There are those who have drawn parallels with the so-called Moebius strip. Look:

http://www.youtube.com/watch?v=xUHQ2ybTejU

Mysterious and fascinating, don't you think?

Open content (youtube)

Mobius, sorry.

Always from Bach's musical offering, an example of a canon by tone:

Open content (youtube)