In 1997 Denis Cohen composed two pieces for soloists and ensemble, Flexus for flute and Plexus for oboe and chamber orchestra.
In Flexus, the composer returns to the materials previously used in Mémoire de Vague for alto and four instruments ( 1996).
Flexus unfolds in three phases. The first is characterized by the alternating flowing textures of the ensemble and the inserts of flute solos whose passages are very rapid, as much as possible, pulsated by the striking accents of the instruments of the ensemble. The principle of alternance can also be found in the constant changes in tempo.
Regular chords announce the second phase. A polyphony of repeated notes effects a change of acoustic orientation. The musical language evolves towards a separation into two homorhythmic groups, and the ensemble freezing suspended chords allows for the development of a cadential flute sequence. Progressively a third phase develops.
The soloist’s playing is singularized, while the other instruments remind us of the forms that have marked the piece from the beginning. The flute becomes piccolo and calms to a very high pitch that brings the music to a quiet and peaceful stop.

Michel Rigoni