We do not know when August De Boeck's Symphonie in sol minor was premiered. The work was in any case performed in 1904 at a concert organised by the Koninklijke Maatschappij voor Dierkunde Antwerpen, better known as the ZOO of Antwerp.
Drama and great emotions are never far away in this symphony: the composition breathes romance. It is also striking that no one would blindly attribute this work to a Flemish composer: the Russian influence is unmistakeable from the outset. The work has been recorded several times, and you can also find and listen to fragments of the Symphonie online.
When leafing through the (autographic) score, it is clear that it has suffered greatly over the years: note the folds, tears, tape remnants, etc. On the last page is De Boeck's signature and the date of completion: Janvier 1896.
You can consult the complete score here.