A renga will start with a three-line stanza known as a “hokku” (発句) which has a 5-7-5 syllable or “on” structure if written in Japanese. The hokku eventually gave way to what is now known as the haiku (俳句), which you can learn more about on this page as well as the significance of syllable count in Japanese poetry. After the hokku is written, the poem is then passed on to another poet, who then follows it up with a couplet, which has 7 “on” per line if written in Japanese. The poem is then passed to another poet, or the starting poet if in pairs, who then follows up the couplet with a haiku, then the next poet writes a couplet, and so on and so on until the renga is “finished.” The last stanza, or “ageku” (挙句), then wraps up the poem as a whole.
When contributing to a renga, each stanza should essentially leap only from the proceeding stanza while still keeping to the central, broad theme of the poem. This is to keep the renga moving and maintain linkage throughout the poem. Personally, this is why I think renga is a cool poetic form: not only do you get an opportunity to collaborate with one or more other poets, thus combining your voice and theirs, it also shows a beauty in connectivity between persons and what they can create together.
There are several traditional styles of renga, each having a fixed number of stanzas, with the longest style being the “senku” (千句) at 1000 stanzas long! However the most favored style is the “kasen” (歌仙) at only 36 stanzas long.
As for modern renga, its typically used as a teaching tool for collaboration, usually in creative writing classes. Like I said earlier, this is mainly because of the renga’s collaborative focus and that you’re combining your poetic voice with that of one or more other poetic voices. Also, there is no defined stanza length for modern renga; in this case, all participating poets should agree when the renga should finish so the ageku can be written.
My first renga I wrote was with someone on Devianart by the name of deinktvis, and here is what we wrote: Winter Renga. It was so long ago since I’ve done this, but it was an interesting and fun experience.
Also on Deviantart, there’s a group called the-haiku-club who not only focuses on haiku, but also focuses on many forms of Eastern poetry (Korean, Chinese, SE Asian, even Middle Eastern) and is the biggest group on DA for such things. Back in January of this year, they held an event called the “2015 January Renga Tree.” Basically, any member of the group could participate and each contribution was a haiku. The hokku for this tree was one that was written by Kobayashi Issa which is as follows:
百福の始るふいご始哉 (hyakufuku no / hajimeru fuigo / hajime kana)
starting the New Year’s luck / first stoke / of the fire
Check out our end result here at 230 haiku! Notice how the renga tree doesn’t just stick to one theme and branches off covering others; it’s pretty neat how some of these just sort of…happened, in a lot of ways it makes the poem as a whole more organic.