Shofu renku? As the courtesan once remarked to the abbot - it looks rather small. So the obvious question, when faced with a yotsumono, is to wonder if it is renku at all.

It depends on what you were expecting. As the abbot doubtless retorted.

Perhaps the oldest form of linked verse, and still the shortest, is the tanrenga - a single exchange of long and short verse between two poets. The yotsumono comes in at twice the size. It opens, broadens, develops and resolves. So, given that the distinction between renga and haikai is one of tone not form, and despite the courtesan's obvious disappointment, there is no reason why a yotsumono, written in the correct spirit, cannot be haikai no renga - aka renku.

But Shofu?

Certainly. If the term haikai is something of a catch-all - embracing everything from Basho's most refined work to the drasty margins of zappai - Shofu is more easily defined. Above all it is a question of aesthetic values. Fueki ryuko, kogo kizoku, fuga no makoto (see Minimum Conditions), none of these rely on length of sequence. The same is true for karumi - the principal driver of his mature style. And short as it may be, there are some aspects of the yotsumono that make it more mainstream than not.

The emphasis on balanced and proportional cadences between verses, and on the poetics of utterance in general, highlights a vital aspect of renku that has received scant attention as the genre has spread into English. The importance of phonology to individual verse structure, linkage, and the wider sense of cohesion cannot be overstated (see Know Your Enemy).

The yotsumono also obliges a thorough facility with the particular characteristics of each constituent verse. Description, furtherance, turn, and outcome. Head verse, support verse, breakaway, and close. These functions are vital to the success of any renku sequence but the yotsumono certainly concentrates the mind. The ageku in particular is placed under the spotlight and can no longer escape by mouthing lukewarm platitudes. Though its task remains that of finding a symbolic and emotional fit rather than providing some form of logical conclusion, it is obliged to be much more focused. We are directed away from a generic sense of closure towards ketsu - an overarching outcome.

More problematic is the question of variety and change. Clearly, at only four verses, the yotsumono cannot contain the ten thousand things of Buddhist metaphysics. Yet this objection may be leveled just as readily at a junicho, or at all poems shorter than the kasen itself. In any event, the suggestion that omni-valence is the product of a surfeit of materials is contentious at best (see Thematic Renku). The anti-thematic, all embracing, nature of Shofu renku lies in its aesthetics, not the quantity of scrawl on the page - or else we mistake effect for cause.

The yotsumono side-steps the issue. Participants are directed to avoid all discussion of their intentions, the meaning of any given stanza, or of the linkage between stanzas, either before or during composition. Ergo - the poem cannot be thematic.

Where it is adhered to, this injunction has the welcome effect of boosting the importance of empathy in linkage and heightening the general awareness of phonics. It also gives rise to an intriguing paradox. A skillfully written ageku generates such a strong sense of coherence across the span of the poem that it feels as if it must have been agreed from the outset. It is a further paradox that any attempt to contrive such an outcome by working to a prearranged plan tends to yield a weaker poem.

Renku is a dialogic form of writing, but it is not just an excuse for some genial chat (see Explaining It All Away). It takes courage to compose a yotsumono on the fly. But the end result may very well surprise.