On 4 September 1917, while he was finishing the orchestration of the Classical Symphony, Sergei Prokofiev began composing a now forgotten score : Seven, they are seven, an incantation for dramatic tenor, choir and orchestra. Prokofiev carefully analysed the poem by Konstantin Balmont, pointing out its salient aspects and designing the shape of its different parts. The composer was then able to sketch fragments of melodies and orchestral passages. The poem, thereby placed in the centre of the creating process, has an unclear history dating from Mesopotamian High Antiquity, and deliberately played down by Balmont. It is thus a very narrow track that one has to follow in order to get the cuneiform Accadian inscription deciphered by Balmont, the evocative power of which was widely exploited by Prokofiev.