Both of these forms are closely related and both, in the simplest of terms, are "songs." The madrigal is, as defined by Lewis Turco, written in lines of either seven or eleven syllables. The poem is comprised of two or three triplets (three-lined stanzas) followed by one or two rhyming couplets. There is no set rhyme scheme for the triplets, so here are a couple of examples of rhyme scheme that may be used:
A**All end rhymes are same in each stanza
**(for syllabic count, use x to count a syllable - xxxxxxxxxxx)
*** (for accents, use dash (unstressed) and slash (stressed); remember, these songs do not count accent)
**** (accent example: -/-/-/-/-/- iambic pattern)
The couplet may comment on the rest of the poem, as in a sonnet, but it may also exist as just another part of the "song" - the madrigal is a form about musicality and sound
Terza Rima Rhyme Scheme
A**As you can see, the terza rima forces you to take more control of your lines
**The rhyme scheme creates a weaving effect that works both aurally and visually
Remember that you can end a madrigal with one or two couplets, so why not try both?
Before I define a Canzone, I'd like to encourage you to give the madrigal a try. Use these steps to get started:
Since this song form was originally about love, try to write about love - any form of love that pleases you. When we start working with rhyme schemes and patterns, it is best to start with broad subject matter so you can find a lot of words and images to fit into the pattern. The sound of the song, rather than the overall imagery, is of most importance. You can worry about imagery later.
Pick out your end rhymes first. It's best to come up with these right away rather than constructing a bunch of lines you can't use. Yes, you will feel like you are shoehorning words, but do it anyway. Give in to the form and let it lead your construction; you may be surprised by what comes about (honestly, though, you will probably be mortified by how awful things come out... but this is an exercise about practice, about getting the form into your blood so you can bring it about naturally later).
Consider your work. Try again. Do not edit. Only edit after you've done a dozen or so of these. Really.
The canzone is a longer version of a song and there is really no prescribed way to write a canzone. However, with that being said, there is a version I was able to find that produces a 65 line poem. The key to this is the use of key words which act as the "rhyming" element. Rather than writing end-rhymes, the poet re-uses key words throughout the lines to cause the weaving effect of the madrigal.
Here's that pattern from Bob Newman's Vole Central:
Stanza 1: ABAACAADDAEE*
Stanza 2: EAEEBEECCEDD
Stanza 3: DEDDADDBBDCC
Stanza 4: CDCCECCAACBB
Stanza 5: BCBBDBBEEBAA
* Remember that, here, each letter is a line, not a syllable/accent
It is incredibly complicated, but lots of fun. Here's the pattern of Auden's poem (notice how neatly Auden ends with a reverse of the first rhyme scheme):
Example: W. H. Auden's "Canzone"
Dear flesh, dear mind, dear spirit, O dear love, - A
In the depths of myself blind monsters know - B
Your presence and are angry, dreading Love - A
That asks its image for more than love; - A
The hot rampageous horses of my will, - C
Catching the scent of Heaven, whinny: Love - A
Gives no excuse to evil done for love, - A
Neither in you, nor me, nor armies, nor the world - D
Of words and wheels, nor any other world. - D
Dear fellow-creature, praise our God of Love - A
That we are so admonished, that no day - E
Of conscious trial be a wasted day. - E
Or else we make a scarecrow of the day, - E
Loose ends and jumble of our common world, - D
And stuff and nonsense of our own free will; - C
Or else our changing flesh may never know - B
There must be sorrow if there can be love. - A