This work could have been called 'In freundschaft'... Following a stroke that could have been fatal, the dedicatee of the work - a long-time friend - lost the use of his right arm. A musician at heart and an excellent instrumentalist, this real tragedy, followed by rehabilitation, so long, slow and uncertain in terms of results, literally stunned me. Evolutive reflects in part this state of affairs and my state of mind in the face of the inevitable. I find poignant and exemplary his current determination not to give up, to continue to teach and to solicit composers to write a short work for him, in a reduced tessitura (only the middle and high octaves produced with the help of numerous substitute fingerings, as the instrument's low octave falls to the right hand). To accept such a request is to be reminded of Ravel and his Concerto for the Left Hand. Writing within constraints - even maximum ones - is not a problem in itself, it is just a matter of accepting them, of 'making do' with them and playing with the inequality of timbre that must be left as it is. The form of the work is the unfolding of a great musical phrase towards the top, constantly thwarted by the use of sonorous breaths, by moments of feverish agitation interspersed with cries, and by great smooth and static descending phrases. These writing characteristics contribute to the strangeness of a time that often freezes and evolves only slowly. In addition to a profoundly sombre character due to the constant breaks, there is something desperate and lamenting in this work: the writing turns on itself like a spiral. The extremely slow evolution of the motifs makes it seem as if they are constantly returning to themselves in the same way, yet it is only a series of variants in the service of a form that is constantly in the process of becoming.