For almost 100 years, violinists had to live without Eugène Ysaÿe's Sonata Op. 27bis. The work was re-discovered in a sketchbook recently given to the library of Brussels’ Koninklijk Conservatorium and is now published for the first time. The Sonate posthume was composed in the surrounding of Ysaÿe's famous cycle of six solo sonatas for violin and shares their artistic quality.