Sillages has been written in the frame of a concert's program on period instruments called Legacy of Bach and imagined by the flemish oboist Frauke Elsen. The core material of the piece derives from the music of J.S. Bach and the harmony is based on a chord progression from the second partita's chaconne for violin. Yet, other influences such as microtonality or non-tempered intervals together with the baroque instruments possibilities interfere with this heritage and lead the music towards new territories.