théo de joncker was a student of august de boeck and paul gilson. for years he conducted the orchestra of the belgian national radio (nir), but he also enjoyed a conducting career outside of belgium. as a composer, he belonged to the brussels group "les synthétistes". this group was found by students of paul gilson as a way to celebrate their teacher’s 60th birthday and included francis de bourguignon, théo de joncker, marcel poot, maurice schoemaker, jules strens, rené bernier, and robert otlet.