Nono belongs to a group of constructivist style works in which the material used (in this case nine notes for nine instruments) determines the pitches and rhythms and conditions the development and duration of the sections.

The overall structure resembles a slow-motion explosion, beginning with a long expansion from the unison to the first tutti, followed by several processes of contraction and dilation, until reaching the slower and softer middle section, where the material stops at its maximum amplitude, as if it were a detonation frozen in time, imploding very slowly from the outer edges inwards.

This is followed by three duets with vibraphone and piano accompaniment, interspersed by accordion solos that fight against the trills of the strings and winds. After a tutti of order-chaos-order, we come to the solo of the percussionist, who struggles to gain the upper hand over the rest of the group, and succeeds in doing so at the climax of the piece. The last section is a retrograde recapitulation of the first, in which the material narrows progressively to unison, and finally disappears.