At the close of the 12th century, as warrior clans began to consolidate their power and bring centuries of unbroken peace to an end, noblemen and women at the imperial court in Heian-Kyō (literally, the peaceful and tranquil capital; modern- day Kyōto) were developing the lengthiest and most complex form in Classical Japanese poetics: the hundred-poem sequence (hyakushu-uta), carefully structured sets of one hundred waka (31-syllable poems). The first 70-80 poems are nature poems. Then follows 20-30 poems about various aspects of human life, including love, religion, birds, etc.What distinguishes hyakushu-uta from other collections of waka are its intra- and inter-textual construction. Key words, images, and phrases recur throughout each sequence. Seasonal images are repeated in the latter human-focused poems, linking the two main sections. A reader well-versed in classical Japanese and Chinese poetry (or one with a well- annotated modern edition) will also recognise allusions to older poems, adding further depth to the web of meanings. Thus each poem, complete in itself, describing a unique experience in the present, also exists in counterpoint with poems of the distant past, as well as within the cyclical structure of the sequence to poems both in the past and future. Discovering this neglected genre had a powerful revelatory effect on me as a composer. These long sequences offered a model of how to capture the brevity of waka and the transient spirit of mediaeval Japanese poetry in an extended form.The formal structure of ephemerons is based on Princess Shokushi's third hundred-poem sequence, which was written in 1200 and is generally considered to be the epitome of this almost forgotten genre. It is divided into nine parts, following the nine thematic groupings Shokushi used in her sequence. Shokushi’s generic titles – ‘Spring’, ‘Summer', 'Love', ‘Travel’, etc – have each been replaced with a phrase from one of her poems. These phrases all relate to water because water – as cyclical and transient as life – is present in all seasons and in all aspects of life. The overall title, emphemerons, is not taken from one of Shokushi’s waka, but reflects the whole sequence’s attention to the fleeting and overlooked.The nine larger parts are subdivided into 100 short sections of roughly equal length, and the music reflects the poems’ themes of observing nature, evoking (through sonic imitation and allusion) the seasonal changes in weather, the land, and animal and plant life. However, this piece is not a tone poem, at least not in the traditional, 19th-century sense. It is not necessary that the listener understand the ‘meaning’ of individual motifs; they are too numerous, often fleeting, and many of the associations are personal to me. What I do intend to come across is the feeling of continuous cyclical change, where each individual moment is itself, unique and whole, but also contains within itself both a past (allusive references to past musics, the piece's underlying mediaeval inspiration) and a future (the cyclical repetitions of motifs and counterpoint of the piece). The multiplicity of motifs and rhythmic freedom for individual players will result in a complex, sometimes chaotic sonic surface. The structure is weblike and cyclical, not linear. Sonic density and intensity are more important factors than pitch or timbre the piece's form. These are all part of my attempt to reflect the natural world.The idea of the future is also expressed in the feeling of transience and fleetingness which is part of the aesthetic of mediaeval Japan, but which, in this era when the destruction of nature is an incredibly urgent problem, is more relevant than ever. This piece is, like all music, at root an exploration of the possibilities of sounds organised by musicians to a greater or lesser degree. But it is also a paean to a rich tradition of nature poetry in which humankind observes but does not interfere with nature, as well as a threnody for the natural world whose near future will, thanks to human interference, be drastically different from its recent past. Like the late 12th-century Japanese nobility of which Shokushi was a member, we in the industrialised self-styled democracies are living in a period of transition, from the relatively prosperous era of the past half-century to a much more precarious one. Our disregard for our own rootedness within the natural world is one of the principal causes of the world's unstable future.