The poetic form renga is composed of linked three- and two-line verses (of 5-7-5 and 7-7 syllables, respectively) alternating in a chain of verses, with each verse written by a different poet in turn.
Renga can be composed by one to a dozen or more poets, with the shortest possible example being a three-line verse capped by a two-line verse. Examples of this form are to be found in the " Man'yoshu ," Japan's earliest poetry collection.
During the Kamakura (12th-14th centuries) period, longer chains became popular, especially the 36- and 100-verse forms. This tradition remained popular until the rise of the very short (17-syllable) haiku form came to dominate poetry in the Edo period. Renga was then transformed into renku by Basho and his followers. Their works, such as "Fuyunohi" (Winter Day), "Sarumino" (Monkey's Raincoat), and "Sumidawara" (Bag of Charcoal), can be found in Basho's "Seven Poetry Collections."
A renga circle usually consists of several veteran poets or a single master poet and a number of participating poets, and a secretary who writes down the verses as they are spoken. The first verse is delivered by the veteran poets or master. It acknowledges the occasion of the poem's creation while also fulfilling the requirement of including a seasonal reference. The second verse thematically follows the first verse, while the third verse changes the direction of the poem by introducing a new motif. This pattern is sustained throughout the poem and helps save the poem from being monotonous. This unique structure enables renga to be appreciated on both the individual verse or couplet level, or as an entire poem.
When the poem is completed, the Master comments on the work, and then the group discusses it. While the individual poets contribute their own links, it is understood that they are there to serve the whole work and not themselves, making renga a unique form of collaborative creation. Thus renga is a textual form that shares many of the spontaneous and innovative qualities found in jazz improvisation.