Joseph Callaerts (1830 - 1901) was the most important Belgian organ composer of the romantic period. I love his music and contributed here his complete "24 Pièces d'Orgue" Op. 20 - 23 and Op. 28 - 31 which contain much musical ideas of Richard Wagner here before.
He studied organ with Jacques-Nicolas Lemmens. Callaerts was organistv at the Antwerpen Cathedral from 1855.
The Grande Fantaisie de Concert Op. 5 is a brillant romantic piece.
Callaerts present himself already with this early composition as an enthusiastic admirer of the music of Richard Wagner. The main subject is very close to Wagner's Arioso "O du mein holder Abendstern" from the opera "Tannhäuser".
I add here my free Paraphrase of Wagner's Recitativ and Arie "O du mein holder Abendstern" as proof for this connection.